Jenn,
I agree that you should get in contact with as many people that can support you as possible. And just stay focused on getting out of that situation, and before you know it you will be able to. All you need is someone willing to rent out a room to you! And who knows: maybe someone at an Al-anon meeting could help you do that, and perhaps for very little money just to help you out. People want to help!
Meanwhile, the fact that you realize everything that's going on, and how terrible it is, is an act of courage and love and heroism. It is in your hands to not let this cycle continue: you can't force your mother to do anything, but you can at least use what you observe to help others, and make sure you never end up in such a terrible situation. Many people in your shoes would simply find someone who does the same things! I know it is hard to believe, and they (like your mother!) would never admit to doing it, but nonetheless, it happens.
Okay Jenn, I want to end this post on a positive note

Stay strong! And don't feel bad about going to a friend's house when things get rough. Or even just get out of the house and go to a coffee shop or something. Or a motel room. Or anything. You come first

Remember that. It's not selfish at all! If you don't love yourself, you can't love anyone!