i'm in my early 20s and at home right now. it's okay. i love my family, but i do prefer living on my own (provided i have friends around... being alone with no one to play with is really unappealing to me.) it's also a little socially embarrassing, but i think i feel more embarrassed about it than most people even care. anyway, i think living on my own makes me have to be more organized, efficient, practical, and self-sufficient.
rebe, you sound like you're ready to go, and that it would be a better situation for you, all things said. there is often low-cost housing for students, especially if you would be okay living with some roommates. your reason to leave is good, just make sure you have an extra pillow of emergency cash should anything happen - what randomnity said. i've heard to make an estimated budget for a month, multiply it times 2 for a monthly allotment (extra can go into savings!), then build up 3 months' worth buffer. i'd stay as long as you need to build that buffer up, and then celebrate your new freedom.
i would definitely talk to the school and see if you can get inexpensive student housing anywhere, or if they know anywhere that is particularly cost-effective. maybe if you built up money for a couple months then moved out, you could handle both school and independence. if the choice does really come down to school or moving out, personally, i would choose school twice over. i have never heard anyone talk about regretting staying with their parents for an extra year or so (not that they necessarily enjoyed it, but it didn't hurt their future in the long run), but i have heard so many people say they wish they'd just finished school. you've done a lot of work already - and life makes it hard to dive back into school once you've left. i'm sorry your situation with your mom is hard, though, regardless.I spoke to my ESFJ friend and basically, the bottom line is, I need to choose either moving out or college is more important to me because I can't accomplish both supremely well, only one or the other. I am already behind in my studies so I want to finish that as soon as possible, but at the same time I want to enjoy my life during the process.