The "Hitman" told the BBC he suffered from depression following the crushing IBO light-welterweight world title defeat in 2009 as his life descended into a battle against drugs and alcohol.
"Being a proud man and a warrior, to get splattered in two rounds like I did, was really hard to come to terms with," he said. "When I tried to get back into training, I realized the hunger was gone and my career was over."
Hatton, who confirmed his retirement in July and now runs a promoting business, said being exposed as a drug taker by a tabloid newspaper in 2010 was a blessing in disguise.
"For someone in my position taking drugs once is nothing short of disgraceful," he said. "The reason behind my actions and the way I was behaving wasn't a drink or drugs thing, it was depression. I was so down, I was crying and breaking out and contemplating suicide."
The 32-year-old added, "Depression is a very serious thing. People don't realize how deadly it can be."