i'm sorry you are going through this. I dated an addict/alcoholic for 2 years and it was tough.
like others said, you don't have to leave now. I knew I was going to have to leave eventually but I realized I couldn't do it until I was ready. Also, I had been doing a lot of "drawing boundaries" then letting him cross them...doesn't do any good. Taught him that I don't mean what I say, that he can disrespect my boundaries, and taught both of us not to trust anything I say. Stating ultimatums without knowing that you can follow through is a bad idea. Say what you mean and mean what you say. That was a big lesson for me!
Other than that, hang in there. If you don't feel ready to leave, don't. I would definitely go to some al-anon though...start working on yourself.