When former army sergeant John Dougan was involved in a car crash, his broken leg was obvious.
But doctors could not see the 57-year-old’s brain injury, and for years he struggled silently with his hidden disability.
Now, after retraining as a teacher, John has spent the past five years helping other brain injury survivors to rebuild their lives, with the charity Headway Rotherham.
And now, his dedication to supporting fellow survivors has seen him shortlisted for the charity's Stephen McAleese Outstanding Contribution to Headway Award.
"I'm pleased that I've been able to help people," said John.
“But for me it's all about seeing people being happy and able to cope with their new life after brain injury."
In May 1995, John was making the 30 mile commute home to Maltby near Rotherham from his army base in Kirton-in-Lindsey when he fell asleep at the wheel and his car smashed into a tree. He was left struggling with fatigue, memory loss and severe headaches, but doctors insisted he would be fine once he went home.
"I was alone all day while my former wife was at work, but when she'd ask me what I had done and I couldn't remember," said John.
"I forgot to take my medication for my leg. I lay awake at night, then I couldn't stay awake in the day. My life was in constant turmoil."
John struggled in silence for years before a doctor finally diagnosed him with a diffuse axonal injury, the widespread tearing of never fibres across the brain. Having discovered a passion for teaching other soldiers in the army, John enrolled at Sheffield Hallam University studying secondary education specialising in DT in June 2005. But the effects of his brain injury made studying a struggle.
"I was one of the quickest in the workshop because I had more experience, but the theory side of the work took me much longer," said John.
"It takes me a long time to read, write and organise my thoughts because of my brain injury, and I was spending countless hours a week on my studies. In my second year I was taking on school placements, completing assignments and doing days at university. I was permanently fatigued."
It was towards the end of his studies that John discovered Headway Rotherham and, for the first time in his life, could talk to other people going through the same struggles as him.
"Up until that point I had felt alone, then I suddenly discovered there was a whole community of people in Rotherham living with brain injury, it was enlightening," said John.
"I found it amazing that there were so many other people like me. There were a lot of people who had it worse than me, who would never be able to return to work, with more physical limitations."
John realised he could support other survivors thanks to his teacher training and life experience - and The Peer Support Group was born.
"Some people had been living with the effects of their injury for 20 years, and they will still struggling to reintegrate into society," said John.
"Some were afraid even to attend Headway Rotherham, and I realised they probably weren't socialising with anyone else at all.
"Since the group started we've had some real success stories. Some people were effectively housebound when they first came, because they were so reluctant to go outside. But as they've grown in confidence they have totally changed.”
The awards ceremony is on December 7 in London.