I don't normally post on this forum and I don't think I've shared this on the forum before, but your situation is pretty much exactly like mine, so let me explain what I have dealt with and what has helped.
I actually have a bipolar mom that I have to live with some of the time and I've been in a similar situation. I have been severely to slightly depressed since I was about 13. When I moved out to go to school, things had steadily gotten better over those last few years. The truth is just that not being around her made things a lot better for me. When I visit my folks for the summer, she steadily starts driving me nuts again, because I just can't put up with her aggression and hypocrisy without it chipping away at me. Truthfully, if I had to be around her all year, I would be a lot worse off, and I didn't learn that until I got some space from my bipolar mom. Several times, I had talked about trying to get a loan so I could pay my own way or join the army, and my dad was good with this, but my mom flipped out and told me I was throwing my life away, that I was trying to punish her and that she wouldn't ever forget about it.
This is why I understand why there's that whole extra obstacle to independence, which is that you will probably be punished for trying not being dependent on her. I understand why this is such an impossible situation because I am still a poor college student, too. I think, though, that what many people may not realize is that more important than moving out is cutting off your financial dependence on her so that she can't excercise that power over you. Also, if your mom is like mine, you would have to go through huge flak for being more independent on top of all the baffling financial logistics. I just got mad one day and made some adjustments to my life.
About your boyfriend, that rings a bell for me too. If he just doesn't understand, you may end up feeling used or hurt. I was more or less misunderstood by various women for a long time in my life. The thing about being depressed is that you're insecure and don't realize that you deserve and can have better. Again, things didn't get better until I cut it off. But being depressed and feeling mistreated from every which way, you're probably also feeling dependent on the people that are there in any way. This is totally understandable but also interferes with your ability to start feeling better.
Do you have a friend that you can rely on? I mean, not hang out with and do things with, but really communicate with about your views on the world, what you want out of life, so on and so forth? And I say a friend because it seems to me at our age that when you remove sex / romance from the picture, especially if you've been hurt, suddenly a friendship can be more transparent.
Anyway, these are the things that have helped me, and I sure wish you luck because I know how hard it is! I think that a person's character isn't measured by how hard they are to knock down, but by the kinds of falls they are able to get back up from.
In Christ,
John
p.s.: There are no doubt great things about you that your own depression will conceal. I myself have some amazing talents that I never realized I had until I became less depressed. The moral of the story is this: I hope the day will come when you will realize that you were wrong every time you told yourself you weren't good for much. I think god can pull that sort of thing off.