Presumably you are either a dealer, or you have a gigantic drug habit?
I suspect that, like many HN readers, I am a young guy who works in technology and makes more money than is good for him. I am single and unattached, so I've got plenty of disposable income. And I seem to be good (so far) at remaining a stable, productive employee despite my habit.
Sometimes it takes a lot of tries, with lots of different kinds of help from lots of different kinds of folks.
Why not spend even one evening thinking it over, maybe talking about it with someone you trust, see what your options are? You are obviously smart and determined, and a drug habit doesn't have to be unavoidable fate.