Originally Posted by
helplessinvan 
Why do I still feel like I haven't won?
Because this isn't a game, it's your life. There is no winning or losing, there are only choices and consequences. You chose him, he chose drugs, and in that way you were exposed to his consequences. You just made a different choice (the right one, obviously), and from that you will begin to have a different set of consequences.
Don't beat yourself up over the past, that's insane. Give yourself time to heal and grow from this experience. To thine own self be true. And consider changing your SR name - that's an appropriate title for him, not you.