The former full-back, who played 86 times for England, admitted he was drinking up to nine bottles of wine a day after his problems with alcohol increased following his retirement from football.
New research has revealed almost a quarter of retired sportsmen admit to health, addiction or financial issues.
Sansom has been sober for more than a month after seeking help from the Professional Footballers' Association, but is wary of any complacency.
"When you come to the end of your career, you obviously have more time on your hands. You drink three or four times a week, then it becomes every day, and at one stage I was drinking eight or nine bottles of wine a day," the 54-year-old told Sky News.
"I was drinking to forget problems and I didn't mind sleeping rough because I'd get miserably drunk and then just fall asleep somewhere on a park bench.
"I can't really say I will never drink again because I'll not only be kidding people watching this but I'd be kidding myself.
"I take one day at a time and today I don't want a drink."
A survey of 1,200 retired footballers, rugby players, cricketers and jockeys by the players' unions has revealed the extent of the challenge facing athletes when they step away from sport and attempt to establish second careers.
The research found that while 79% of former sportsmen said they were content with their lives, 32% said they did not feel in control of their lives in the first two years after leaving sport.
And 24% said they had suffered from physical and mental health issues or financial and addiction problems as they sought to move on from professional sport.
Some 16% said they experienced depression or "feelings of despair", 17% had anxiety or stress, and 16% suffered a loss of self-esteem once they retired.