One minute, Darren Eadie was the Premier League footballer who Martin O'Neill had paid out £3.5m to bring to Leicester City. The next, he was lying in a hospital bed, his arm covering his face, trying to take in a surgeon's words that his career was over.

Later, he would be hit by a depression so deep that it left him driving around the country lanes of his native Norfolk, so traumatised that he had to stop and call his wife out to come and rescue him. The same illness left him unable to go into the sea with his children on holiday, or to complete a birthday meal with his wife when the panic which was regularly seizing him took over once again. But to begin with, it was only the little things that hit Eadie as he went through the motions of packing up his life and career in a bag, at the Leicester City training ground.

"Everybody says you hang your boots up when your career is finished," Eadie says now. "But you actually take them down."

His story, which asks questions of whether football does enough to help those players who are thrown out before they are ready, begins in the bed of a private hospital in Leicester in 2003, where Eadie was trying to shake off the effects of an anaesthetic, after his third operation in one year on his left knee. It was surgery carried out to find out the effects of what had been the last roll of the dice – pioneering surgery, carried out on Eadie in Sweden 12 months earlier by the surgeon Lars Peterson, whose technique was to re-grow part of the cartilage in a lab, then inject it back into his knee via three grafts. It was a relatively new operation but it had worked before and it would do so again, notably when Manchester United's Ole Gunnar Solskjaer needed help.

Eadie had encountered problems with his knee before but had always overcome them. A crunching tackle by Scott Parker, 40 minutes into Leicester's game at Charlton on 1 April 2001 was different, leaving him sidelined for months and unable to get back playing. He never would get back. The knee never felt right after the Swedish surgery. When running one day he felt "something go" in it and it emerged that one of the grafts had fallen out of place. A repair took place, Eadie went back to the gym, but he felt the same problem. All three grafts had fallen out and that was when more exploratory surgery – in the Leicester hospital – brought him to his moment of truth with the surgeon and Leicester physio Dave Rennie.

"I just knew by the look on their faces that the news wasn't good but the words 'I'd advise you that it would be in your best interests to give football up' were shattering," Eadie says.

His wife, Kelly, was told by Rennie that she should get to the hospital as soon as she could. She immediately knew that the situation was not good. "I can remember walking in and seeing Darren lying on the bed with his arm covering his face," she recalls. "It was a massive blow for him, knowing that his football career was over, and it affected all his family too, as our family life was also based around Darren's footballing career."

Eadie's first instinct was panic. He was a top Premier League footballer at the time, earning good money. "When I got home and spoke to all my family on the phone, I wasn't sure what to do. My first thoughts were that money would be an issue and I'd have to sell everything to get by. It was unrealistic to be driving around in a Porsche any more. Everybody did their best to keep my spirits up, but the unknown was frightening." He recalls his final day at Leicester when he said his goodbyes, collected his belongings and walked into the boot room to take that pair of his down off the peg.

"That was probably the worst moment," he says. "Being told in a hospital environment wasn't great but going to gather my football bits together, knowing I was going to leave, was the hardest moment." It was after selling up in Leicester and moving back to the family home in Norwich, that he was finally confronted with the enormity of what lay in front of him.

"At first I was OK. It was nice being back among family and friends. I just thought I'd be able to sit around and do my own thing. But things started to change. People I'd started to trust in life let me down. In football and inside the changing room, everybody is pretty much in the same boat and same position in life. You all trust each other and the camaraderie in the team brings everybody closer.

"On the outside, things are different and you soon realise that you can't trust everybody. I was involved in a couple of business ventures that didn't work out. People that I thought had my best interests at heart didn't. It is hard when the only thing you know is football. I would go into Norwich and walk around and see everybody else was happy and it depressed me even more. It was a vicious circle. Then the panic attacks started and it was completely debilitating. I'd end up having to call Kelly to come and get me. It was really scary and it paralysed me at times. It would happen up to three times a day, and cause pain in my arms and other places in my body."

The news that his mother had been diagnosed with breast cancer – and had been made redundant – was another blow. "That was devastating, of course. Thankfully, she has had an operation and treatment and is making a great recovery. But… depression is a very lonely place, even with all the support around you. It's only in your head. I can remember driving one day in the country lanes around Norfolk and not being able to go any further. I had to phone Kelly up to come and get me." Had he considered taking his own life? No, he says. That is something he could not put his family through.

His wife lived through the depression too. "It was like looking after another child," Kelly says. "I didn't really have anybody to seek guidance from. It was very lonely and it certainly put pressure on our marriage. I didn't realise depression could make you so physically ill at times.

"What Darren was going through shocked me, and at times it made me feel numb. I wanted to run away but I was the one keeping the family together. I needed help how to deal with the illness. Football ruled our lives when Darren played. He told me one day in the middle of all this that he could never see himself being happy again. He wasn't able to go running for four years after he finished football. He couldn't even go out in the garden and play with our son, Taylor. Even on holiday in Cornwall he wasn't able to go in the sea with the kids."

Her birthday meal, when the two of them went out together, is one of the moments she remembers. "Halfway through, Darren started to get really upset and panicked. I had to quickly get him out of the restaurant and pay myself. It wasn't the birthday that I expected but the bigger picture was more serious." Eadie knew he needed to seek help. "I saw doctors and other people as well. Everybody was really good with me, especially Leon McKenzie, the former player, who had been through a similar experience."

But the help that came from within the game was not all it could have been, he says. "I was disappointed with the help that came from within the game. I spoke with Professional Footballers' Association chairman, Clarke Carlisle, who was great, but overall I found the PFA disappointing. When Gary Speed died, the PFA said they would be sending out leaflets to all ex-players about life after football, but nothing ever came through my door. I found myself waiting every day for it to arrive. There needs to be a place sportspeople can go to sort their heads out. Treat the early stages of depression and it could stop the addictions like gambling, drink, drugs starting. People start these when they are feeling at a low."

Like most people fighting depression, it was the solace of his family which helped most, although Eadie was astonished to discover so many others had been through the experience. "People have a perception about footballers being egotistical big-heads. Don't get me wrong, there are some of them, as in any walk of life, but most of them are not like that and depression is not an exclusive club. Wealth, race, age, gender – it can affect anybody at any time. It really is so important to talk and seek help. You will be amazed at the response."

Eadie has made it through and today finds himself in a better place. He works in local radio, enabling him to keep a close eye on his former teams Norwich and Leicester, and also for Sky Sports and other media. He has established a charity website – www.sellebrity.org.uk – auctioning celebrities' clothes and other items they no longer need. Beneficiaries include the Prince's Trust, of which he is an ambassador. He has also been involved in an enterprise to launch a new energy drink, EQ8, made from natural ingredients.

Where the future is concerned, it is still "one step at a time for me, so early on," Eadie says. But he has found focus. "I want to be just as successful in something else as I was at football. I am now working with some lovely people and I'm determined to make it all a success for them as well as myself. Things like this make you better and stronger." The last few years have been long but now he can really say that he has taken those boots down.