Dear SiRi, I am so sorry you are here yet so happy you found us. I want to reach through this computer and hug you tight. I lost a very dear friend 10 yrs ago who was in your same situation. She didn't know how to get away, what would happen to him? It all got out of control one night and he killed her. Anyone who met him thought he was actually a nice enough guy. He killed her.
Alcoholics aren't abusive because they're alcoholics. Abusive people get more abusive when the alcohol takes away their inhibitions. You are dealing with an abusive man who is also an alcoholic. There is no future in that. He will continue to make you feel crazy, continue to make you feel isolated and afraid. The nice guy you see on occasion and the abusive drunk are not 2 people. They are one guy...and you will see less of the nice guy as his disease progresses. And you will become more and more at risk.
You are so blessed to have supportive family who can help you free yourself. Call the DV hotline near you, they will help you set up a safe exit plan. Then. Get. Out.
Your credit and finances aren't going to get any better by staying. He managed to get along before you came along, he'll manage when you leave. A's are brilliant manipulators...they always manage to get by. He is not your "project", not yours to "fix". He's an adult, and he has the right to drink if he wants. But he doesn't have the right to abuse you. Get out. It's a scary thing to do. I heard someone in an AlAnon meeting say that although they were fearful, they learned that their happiness was on the other side of their fear. The only way to get there was to push through the fear.
Keep posting here, we're with you every step of the way. Read all you can about alcoholism. Find an AlAnon meeting near you and try to attend a few meetings. Maybe your Mom or sibling will go with you initially as support. It's an amazing place to get the support and tools you need to move forward. There is a very different, peaceful life waiting for you.