I don't really know what to say except I feel for you. I went to a divorce and separated group at church (a few years ago), there were two women with alcoholic husbands. One had come to peace with her decision to leave; one was looking for peace. Basically, they both hit that point where they had given as many chances as they could. The long and short of it was they just couldn't take it anymore.
As for why they kept giving chances, they were married. They were Catholics with a sacred view of the union. Only you can determine when enough is enough.
