I know you are hearing a lot of people saying leave. I have been sober for a while, 26 years and what I have found is that people who get sober for other people don't always stay sober. It becomes too easy to slip and blame the other person. They also tend to resent the person that is keeping them from it. You are only 25 and you are trying to bear too much responsibility on yourself. It isn't easy especially when he hasn't really been able to stay sober. He may when he realizes that you aren't there. I had lost everyone. I told myself that I was ok. I kept drinking, going home with people I didn't know trying to convince myself that it was ok. I lived in a boarding house barely surviving. I know for some that isn't a low bottom but it was for me. I had to feel all that pain before I could realize that I had to do something for me. That's when I could finally surrender. Maybe he now needs to find his own bottom. Then he can change.