At the peak of his career, O'Connor was earning £18,000 per week, but has revealed that he got "carried away" with his spending.
"I knew I should never have put myself in that position but when you've got that much cash sloshing around you get carried away, " O'Connor told the Daily Record.
"I always found myself in the company of people who had coke on offer all the time. It was too easy to take the drug on a night out.
"I've certainly not spent much cash on cocaine - it was always just put my way by so-called friends."
O'Connor has 16 Scotland caps to his name.