They were probably not the words my sister expected to hear but in the early weeks following the blast, as my body was gripped by infection and my organs started to give up one by one, the only words I managed, whispered into her ear, were: “I’m still a photographer.” They may seem ridiculous but they were my failing, broken body attempting to retain its identity, to grasp on to that which still defined me, beyond my injuries, my blurred consciousness and impending induced coma.

A few months earlier, I sat in the searing heat of Sudan with Gino Strada, the charismatic chainsmoking surgeon who set up the Italian NGO Emergency, discussing the plight of civilians caught in the Afghan conflict. I was visiting their project in Khartoum, documenting their groundbreaking Salam Cardiac Centre. Over dinner, Gino told me about the work Emergency was doing in Kabul. I had shied away from Afghanistan because I felt so many great photographers were already working there. I’ve always said that if I get somewhere and there’s another photographer there already, I’m in the wrong place. My main interest has been the untold stories of human suffering around the world. However, as Gino explained, with his typical Italian passion, about the plight of civilians caught up in the years of conflict, I realised it was a story I had heard little of. So I resolved at that point to go and document Emergency’s work there, and I made that promise to Gino.

A few months later, I found myself in Afghanistan. In the period before I was due to start my work in the Emergency hospital I was embedded with the American 101st Airborne. I was setting up Document – my own publication for documentary photography – and as part of that had decided I would do a story on the impact of war on a small unit of soldiers. To create a fuller picture I wanted to try to document all sides of the conflict, to show that in many ways all those involved in a war can become victims. It’s an amazing statistic that last year more US servicemen killed themselves than were killed in Afghanistan.

While on this embed, one cold morning in February 2011, I stepped on an IED (improvised explosive device), which had me fighting for my life in intensive care for the next two months and left me a triple amputee with only one arm intact. As I regained consciousness in the Queen Elizabeth hospital, Birmingham in the months that followed, I started to become fully aware of my situation, and one thing became quickly apparent; it seemed highly unlikely that I would work as a photographer again. In fact, during those early stages I was told I’d probably never live independently. It felt as if my life was over. And in many ways, guilty as I feel to say it, I wished I hadn’t made it.

Yet those around me, my family and my partner, Jen, encouraged me and rekindled my fight. Stubbornness – which as a child I was told would be the end of me – was starting to become my greatest asset. Lying in the hospital bed, I resolved that I would not only walk again but would have my life back as it had been before I stepped on the bomb.

Three months later, when I sat up unaided in my bed for the first time, that seemingly simple task felt like the greatest victory. And from that point I knew I could make it. To push myself, I set goals: to walk unaided by Christmas; to have a drink in my local, the Hastings Arms; to walk with Jen in Soho, the place where we’d had our last date; and within a year to have had all my operations and to be living in my own place. Each goal was reached and ticked off until there was just one left; the most important and the most challenging. I was determined to keep my promise to Gino; to return to Afghanistan and finish the project I had started.

As the plane lands on the tarmac of Kabul airport I am filled with a nervousness I’ve never experienced. I’ve been thinking of this moment for two years. I’ve worked tirelessly to achieve this goal, and now it’s here I am, quite frankly, shitting myself. I’m wondering, “Why did I do this? Why did I come back to the place that took my limbs and so nearly took my life?” Nobody would have thought less of me for not coming back. My family and partner hoped I wouldn’t. My body hardly helps, and for weeks I’ve been unable to sleep at the thought of it. Yet here I am back in Afghanistan.

This time I’m not alone. Right from the moment I arrived at the QEH just days after the explosion, while still in intensive care, people wanted to tell my story and record my recovery. I wasn’t particularly interested – telling my story didn’t seem that important. As time went on, though, I realised that because of what had happened to me the work that I did would get more attention. One of the hardest aspects of the work I’ve done for 10 years, documenting lesser-known humanitarian issues, is getting people to actually see it. It became clear to me that my story could be used as a way to tell other people’s stories. The way I see it, what I’m doing hasn’t changed but my voice has got a lot louder.

The offers to make a documentary ranged from Jamie Oliver’s company to South Korean TV but for me it was important to find a team who were as interested in the current affairs angle, in the stories I was documenting, as much as my story. I didn’t want it to be about me. So when I was approached by the team at Channel 4 responsible for Dispatches and Unreported World, two of the documentary strands I really admire, I jumped at the opportunity. I knew I could trust them to do it right. Now they are in Afghanistan with me and the reality of making the film is upon us all.

As we leave customs and sit by the exit waiting to be picked up, I’m filled with overwhelming dread. I’m convinced there is about to be an explosion. My logic is telling me it’s unlikely but something inside reminds me that that’s what I thought last time. My battered mind is conjuring an imaginary blast so real I can physically feel the heat. I have never been a brave man but I’ve never felt fear like this. As we drive through Kabul my fear grows. At each checkpoint, each traffic jam, every obstacle, I think I’m going to be sick. I put my one good arm between my prosthetic legs with the ridiculous logic that, if there were a blast, it at least would be protected.

After 20 minutes we reach the Emergency hospital in the city centre. The hospital was set up in 2000 when the Taliban bequeathed a former kindergarten to Emergency as its first hospital in Afghanistan. At the time it was the only intensive care unit in the country. In the grounds, playground slides and swings remain, eerie reminders of the hospital’s more innocent past. When we park the car I am greeted by Lucy, a British nurse I became friends with the last time I worked at Emergency’s hospital in Sudan. We feel relieved to have a moment of familiarity in a foreign place. Out of respect for local custom, I resist the urge to put my arms around her until we are in private. “My God Lucy, it’s so good to see you. I promised I’d be here.” And at that moment the tears take over. Two years of fighting for this moment overwhelm me. I have really made it.

One of the things I learned about Emergency in Sudan was the care given to the grounds of the hospital. It is part of their ethos that a hospital should be an oasis of calm as much as a centre for medical treatment. While most hospitals in conflict areas are naturally chaotic, Emergency hospitals always have a sense of peace. The hospital in here is no exception. As Lucy takes me on a tour through the manicured gardens where patients relax in the sun, it is hard to believe I am in the centre of Kabul.

But the appearance belies the reality. Each day the hospital deals with up to 30 civilians injured, often horrifically, by conflict in Kabul or nearby provinces. It has a policy of treating only war-wounded – only those with injuries from bomb, gun or knife are admitted. Before I arrived Lucy had sent me several emails which gave me a sense of the place. In the staff room I ask her about some of the stories she’d told me. During the summer, she says, the casualty rate was so high they had patients in the laundry room. A couple of months ago, they had six patients from the same family. They’d been in a bus that had driven over a landmine. Several died at the scene. They had a grandmother, her daughter and her grandchild all in the same ward. The mother had lost her legs. She tells me of the boy who prays each night after losing his sight when his brother detonated a landmine. They asked his family, “What is he praying for?” The family replied: “He prays to forget because the last thing he saw was his brother being killed.”

The conversation is interrupted as her walkie-talkie crackles into life. She jumps up and leaves the room, explaining that it’s another casualty and that she’ll meet us all later in the staff house. She had been talking nonstop until this point, as if the process of recounting so many stories is somehow cathartic.

There is one particular benefit of working with an Italian NGO – the staff all live as one big familia. On that first evening we are treated to a group meal that belongs more in Naples than Kabul. With laughter, hugs, Parmesan and pasta, the only thing missing is red wine. Throughout my career I have always had the deepest respect for those nurses, doctors, surgeons, logisticians and administrators that give up their lives to work in hospitals such as these around the world. They sacrifice families, their freedom, risk their lives, put their careers on hold but rarely to any fanfares. Despite the laughter tonight, I can see the strain. Confined to the hospital grounds, working seven days a week, on call 24 hours a day, they have grown used to the sound of suicide attacks and gunshots and dealing every day with horrendous, needless casualties. I only wish they more regularly received the praise they deserve.

I go to bed exhausted but unable to sleep. All I can think of is how I will cope tomorrow and if I will be able to do my work. The reality has struck home. This is no longer about me ticking off my final goal; I am now here to do my job.

The following morning we drive across town to the International Committee of the Red Cross limb-fitting centre. As well as showing those recently injured, I want to document the long process of rehab and the lifelong impact of many war wounds, especially amputation. While wars come and go, their legacies remain. In hospital in Birmingham I’d learnt about Alberto Cairo, who runs this centre. “Mr Alberto”, as he is known, gave up his career as a lawyer in his native Italy and retrained as a physiotherapist to dedicate his life to helping others. Somebody had played me his TED talk, Scraps of Men, where he explained the value of not just getting someone to walk again but in helping them rebuild their lives. What is the use of a person who walks again but has no future? Alberto has run the centre for more than 20 years, supplying prosthetic limbs for the war-injured, even under Taliban rule. He truly is an inspirational man and I am excited about meeting him. As our vehicle pulls up into the compound, he greets me, a tall, spindly figure who, despite being in his early 60s, has the energy and cheeky glint of a teenager. Before I’ve even taken my first steps with him he is examining my legs and commenting on my imperfect gait. “Have you been on a bicycle yet?” I laugh. He looks back quizzically. “No, I’m serious. Why haven’t you been on a bicycle yet?” Very quickly it becomes apparent that Alberto is not a man who accepts the word impossible.

He shows me around the hospital, an amazing facility that has become virtually self-sufficient. Once amputees have finished their rehab, many are given opportunities and training in the workshops to produce limbs for the next generation of amputees. They produce a staggering 15,000 legs a year, largely made from recycled materials. It’s a fantastic approach that creates a sense of solidarity and refuses to see those injured as disabled. Very early on, they are taught that they have worth. One of the great problems for those who lose limbs in less developed countries is that while they may recover from their injuries and achieve some mobility, the difficulties of access to facilities and prejudice means many find it impossible to work. We haven’t gone far when we come across a young man having his first casts made. He has lost both legs, one above the knee and one below, exactly the same as myself. The technician is preparing the plaster to take the mould of his legs. Those around me comment that it must be such an amazing time when you finally get your legs. My heart drops at the memory though. While I understand that for an outsider it may seem a positive step – you’re finally on the road to getting your prostheses – what struck me when I was first measured for my legs was the reality of my situation. Most of the time when I was in hospital, while the recovery was slow and arduous, I noticed day-by-day improvements in strength and ability and movement towards a full recovery. However, sitting there on the prosthetist’s chair was the first time that I truly grasped the reality that I would have to live my life without legs.

I ask the young man if I can take his photograph. He nods. In the tight space I manage to lean against the wall so I can lower my angle and take my first frames. I am struck by the blankness in his eyes. I stand up and turn to walk out of the room. Alberto puts his arm around my shoulder. “Congratulations,” he says, “you’ve taken your first photo.” There is a small sense of pride but it is overwhelmed by a terrible guilt that once again my work means I am intruding during the hardest moments of people’s lives. I feel more ashamed than victorious. As we are leaving, Alberto introduces us to his cat, Rita, a stray who one day walked through the gates and into his office. Now she never leaves his side. She is missing a leg. In Kabul, even the cats know where to go.

Over the following days I slowly get back into my stride. For two weeks I am based at the Emergency hospital, documenting the patients there. I discover new challenges, the greatest being how to balance. The average person uses three mechanisms to control their balance; their feet, the inner ear and eyesight. The bomb has robbed me of my feet and damaged my inner ear, and I discover that when I close my eye to look through the camera’s viewfinder, I lose my balance. On top of this, I am learning how to hold my heavy camera, balancing the lens on my left stump. My greatest fear is that my photographs will not be of the same standard as before my accident. And the first few days do little to assuage that fear. Each night I look through the day’s photos with a heavy heart. I seem incapable of capturing the stories of those I meet. However, I am also aware that on many assignments the first few days or weeks are always the hardest as I settle into my groove. Every place you photograph has its own rhythm that you need to understand before you can truly capture it. In the past I’d always prided myself on how boring I was. No matter where I was in the world, people rapidly forgot I was there and I could drift into the background, giving me the opportunity to take photographs that did not seem staged. With my shiny new legs and one arm, being anonymous is proving much harder. On the plus side, my new condition is creating a connection I have never experienced before. I find myself in long discussions with those who have recently lost limbs or are about to, relaying my own experiences.

One day I talk to a young boy, Sediqullah, and his father, a sturdy man from the Panjshir valley. Sediqullah’s hands are bandaged and his face pitted by shrapnel as a result of an explosion. They explain how he, as has happened to many curious boys, found an unexploded fuse that exploded in his hands. His father also shows me the wounds he received during the Russian occupation. A missile landed near him, shrapnel embedding itself in his neck and body. Those around him assumed he was dead and he was put in a coffin, only to regain consciousness at the last moment. I look at him and joke, “Well, I guess there are two empty coffins waiting for us.” He laughs and puts his arms around me in a bear hug.

Over the following days I grow closer to Sediqullah and his father, and when it comes to his next operation Sediqullah asks if I will be in the operating theatre. The men from the Panjshir valley in northern Afghanistan are famous for their strength and tenacity, and pride themselves as being the only valley in Afghanistan that has never been conquered by the British, the Russians or the Taliban. As they wheel Sediqullah into the theatre you can see that same pride and dignity in his face. He looks at me and smiles. As he is put on the operating table, they lay his injured arms out, and although I can tell he is scared and in pain, he stares at the ceiling with a sense of defiance. I raise my camera and take a few frames before giving him a thumbs-up and a smile while the anaesthetic takes effect. I watch most of the operation and then leave to talk to his father. He wants to know how bad the hand injuries are. I am possibly one of the few people in the world who is in a position to say, “It’s OK. He’s just lost the ends of a few fingers. It’s nothing.”

Once more his father roars with laughter and puts his arm around me. That evening, once I get back to la familia, I nervously edit that day’s photographs. Instantly, the photograph of Sediqullah with his arms outstretched, his eyes defiant yet somehow innocent, jumps out at me. I’d got it. Lucy looks over my shoulder and smiles. “You see, you never lost it. I knew you could do it. I’m proud of you.”

As my confidence grows and I become more familiar to the patients, I start once more to blend into the background, focused on telling the stories of those I meet. The hospital can be a heartbreaking place. Each day we rush to the ICU as new patients arrive, all with horrendous injuries. Many of them won’t make it. Many have terrible stories of how long it has taken to get to the hospital. A boy appears who had been hiding in his aunt’s house during the night as a gun battle took place between American forces and the Taliban. A bullet came through the wall of the mud house and entered his shoulder before shattering his jaw. For 10 hours, all he could do was lie there with his screaming aunts, waiting for a lull in the fighting. Eventually his father was able to get to him and drive him for a further 10 hours to Kabul. This story is typical of so many. Yet one becomes aware that, for every person that survives such a journey, many cannot make it. I reflect back on the story Lucy told me, of the three generations of one family all injured at the same time in a neighbouring province. It took them 17 hours to reach the hospital. It took me less than 30 minutes to get to one after the explosion yet it seemed like the longest time in my life. I imagine what must have gone through that mother’s mind throughout that journey, not only her own suffering but having to bear the suffering of her daughter and mother, unable to help.

Each patient I meet has a heartbreaking story – at times they are almost impossible to comprehend and digest. One man looks after his paralysed brother, Najibullah, daily; Najibullah was in a bus when a US missile struck nearby. Shrapnel lodged in his spine. He is growing weaker by the day and the doctors confide to us that he doesn’t have long to live. Yet each day his brother tirelessly cares for him. Never without a smile, he strokes his hair, lifts his spirits with jokes and gently cuts fruit, which he feeds him. He tells us his brother was the smart one at university and was always the baby of the family, which is why he looks after him. Without fail, every day, the older brother greets me with a smile and hands me a piece of apple he’s just cut. I find it unbearable to see the love yet know the fate. It’s so easy for us to hear stories of wars on the news and not relate, because of cultural or religious differences, to those who have to live through them. Yet, at the end of the day, across the world, I have always found people are just the same; the same dreams, the same hopes and the same desire for their loved ones to live in safety.

One thing that strikes me throughout the visit is the lack of medical facilities in this country. The Emergency hospital in Kabul and its outlying stations are one of the few free medical facilities available to Afghans and the only hospitals truly catering for those caught up in the war. After more than 10 years of being in Afghanistan, during a so-called “nation building process”, we are yet to build one functioning hospital. Whatever the rights and wrongs of this war, I can’t help feeling that if we prosecute a war in another country, we have a duty of care to civilians caught up in it. Whether it is our weapons or the weapons of the Taliban that cause the injuries, for us to claim the moral high ground, and to win “hearts and minds”, we must care for civilians. Beyond that, though, simply as humans it must be our duty to help those in need.

The Afghan people have never ceased to amaze me with their tenacity and strength. Most of those I meet on this trip have only known war. Most have grown up in an environment of violence and death. Emergency has treated 3 million Afghans, and that in a country whose population is only 28 million. It’s an amazing statistic but despite these hardships people are positive, and in all my travels I have never seen such compassion for others. What also strikes me is the way I am welcomed. Every day both patients and staff throw their arms around me and thank me for coming back. Afghans are a proud people and don’t want the world to associate them with the Taliban. On more than one occasion I am confronted by somebody in tears, saying, “This was not the Afghan people that did this to you.” For what it is worth, I never thought it was either.

As the days go on, my photographic story comes together. I have always struggled with the quality of my own work but despite my misgivings about the photos I am taking I can’t honestly say they would have been any better two years ago. On the penultimate day we return to the ICRC for a final day’s photograph. I don’t feel the need to take many more photographs. However, as we are preparing to leave, we meet a boy, Ataqullah, and his father. They have come in so that Ataqullah can have a new leg fitted and try a prosthetic arm for the first time. Just over a year ago, while walking to school, he stepped on a landmine. His brother and nephew were the first to reach him and raced him to his father who then drove him eight hours to the Emergency hospital in Kabul. He never lost consciousness during the journey. People always ask me if I ever cry taking photographs, if there’s ever a point where it just becomes emotionally too much. The reality is that, no matter how difficult the situation, I somehow have always managed to take the photograph. It’s as if the camera acts as a barrier, a shield, protecting me from the horrors I’ve encountered; a man blinded by acid in Bangladesh, a child shot in the stomach in Sudan, a woman injured by a mine in Angola. To me, taking a photograph has always seemed an act of professionalism born out of a desire to take the best picture possible, to tell the subject’s story as honestly as I can. It’s when I get home that the photographs really hit me. Seeing the faces in my dark room or on my laptop screen brings back the hidden emotions and memories, often leaving me in tears and unable to carry on with my work. As a photographer, I’ve always felt I was doing the right thing; as a man, I’ve often been left feeling like a vulture, guilty for doing my work. Yet I’ve always persevered, somehow able to detach myself.

But today is different. Through my viewfinder I am watching Ataqullah clumsily struggling to take his first steps on the new plastic leg while his shattered arm swings beside him. As we follow him into the limb-fitting area he is engulfed by prosthetists and doctors. All I can see is a small, lost child, bewildered in a sea of adults. They poke and prod, attaching straps and plastic limbs while Ataqullah stares blankly. I raise my camera, trying to capture the scene in front of me, but all I can think of is everything I have been through in the last two years, and how, as a 40-year-old man, that had nearly broken me. All I can think is that no seven year old should have to go through what I went through. That no seven year old should be maimed in such a way, left with a legacy of pain and disability, blown up when walking to school. I can’t take my eyes away from his glazed, lost expression, his eyes, as big as saucers, staring blankly back at my camera. For once, I can’t take it any more. I put the camera down, my vision blurred with emotion, and I leave the room.

Before coming back to Afghanistan I was worried I would not be able to take photographs again in the way I used to, that my injuries would leave me incapable of the movement and guile needed to be a good photographer. I never wanted this to be a vanity project. I didn’t want to come here just to prove I can take a photograph, I just wanted to do my job. Photographing injured people is intrusive and difficult, and comes with a responsibility. Now, though, I’m discovering that it is maybe not my physical abilities that are hampering me but my emotions. I take my last frames and know my work in Afghanistan is done. I just want to get home to be with Jen and my family.

Since returning from Afghanistan I’ve had time to reflect on my trip and whether it was worth it. People ask me: “Don’t you regret going there the first time? Is any one photograph worth losing your legs for?” It’s a stupid question because of course no one image is worth that cost; but I’ve always believed that the principle is. Ironically, I believe that stepping on a bomb, and the suffering that continues, confirmed to me that going to these places to tell these stories was and is the right thing to do. Each day I cope with my injuries; they act as a reminder that in the world there are thousands suffering from similar injuries yet without the medical and emotional support I have. They suffer without voices, and, thankfully, despite everything that’s happened to me, I remain capable of telling their stories. How could I not carry on with that work? More than that, I honestly believe this whole experience has made me not just a better photographer – more considered, passionate and with greater empathy – but also a better man. I will forever be in the debt of those who made this journey possible; the medics, nurses, surgeons, physios, friends, family and Jen.

Recently Jen and I were asked what we wished for in the year ahead. We both said we hoped for the most boring year of our lives! I dream of Saturday nights watching TV and eating takeaways with a glass of wine. More than that though, now that I have done this film and am once more telling stories, I hope I can draw a line under this stage of my life and move on from being the story. As every injured civilian in Afghanistan deserves, I want to be defined not by what I’ve lost or what has changed but instead by who I still am. One day, if they write an epitaph for me, I hope it will not say I was a triple-amputee, instead just say that Giles Duley was a photographer. For that is what I am.

Walking Wounded: Return to the Frontline will be shown on Channel 4 at 10pm on 21 February