I'm sorry you're hurting...but it's time to let him go. Nothing you did or didn't do, were or weren't, are or aren't could fix his alcohol addiction. If he's on his way out of the grip of it, great...wish him well from a distance and move on.
I think that sometimes we as women are biologically programmed to nurture and stay the course. After all, what happens to the species if we abandon our children when they're demanding or difficult? That nurturing instinct doesn't always serve us well if we get focused on "fixing" other adults who need to be responsible for themselves.
But I do think it makes it harder to walk away.
Wish him well and and move on. It's not your responsibility.