The 32-year-old Somerset opener's dramatic decision to fly home from India and quit just before facing Australia in 2006 because of a 'stress related illness' sparked speculation about the state of his mind and his marriage.
Now, in extracts from his autobiography, which is being serialised in the News of the World, Trescothick has admitted he was suffering so much he believed he was dying and even considered self-harming.
Describing his descent into depression in India, Trescothick said: "I was petrified. I started sweating heavily and shaking. My mind was racing. And I could hear a loud thumping noise - like someone banging a big drum. I couldn't work it out. Then I realised it was my heart.
"Exhausted, emotionally vulnerable, isolated and far from home, I was ready for the taking."
"For a moment I was convinced I was dying. I knew I was in serious trouble...I had to get help."
Trescothick, who was standing in as captain in place of Michael Vaughan at the time, immediately flew home to join wife Hayley and daughter Ellie, but even that couldn't stop his downward spiral.
He explained: "Out of the blue, in front of Ellie and Hayley, I felt a massive surge of anxiety overwhelm me like a huge wave. It sucked the breath clean out of my lungs. The next 48 hours were hell.
"I started thinking seriously about doing myself harm. I knew I didn't want to carry on living like this."
He attempted a comeback at international level and even went on the ill-fated 2006 Ashes tour, but it soon became clear he was not fit for duty.
Reflecting on his final appearance for his country, in a warm-up match against New South Wales, he said: "It was as though someone flicked a switch. I knew it was over. The tears welled up as I started to walk back to the pavilion.
"I knew I no longer had any say in the matter. The illness had come back. The thought of what I was doing hit me like a kick in the guts. I would probably never again experience the great highs, hard work, and joy of playing for England."
Trescothick has enjoyed a successful season with Somerset in county cricket this year, becoming the first player to hit 1,000 runs in Division-1 of the County Championship.