Been in that kinda situation myself. Feels much better once you free yourself from it. As others mentioned too, why can't you rent a flat [appartment] to live in? Especially with other people to share the bills with you.
and this is one of few situations I have to say, there is really no chance that relationship is going to work. Even after opening up a realtionship, she still can't be open herself? She's the kinda person who convinces herself that she's always right by blaming everyone around her for whatever happens to be going wrong at the time... going as far as telling YOU that if YOU can't fix HER problem, within as little as a week, it's over between you both.
I can imagine that once that does happen, because of course you can't fix who she is in a week, she will see it as a victory for herself and continue being the same person she is to everyone else.
Get out of there. Have some you time. Don't look for a relationship for the sake of it. Someone will find you when you least expect it. I promise that.
Then once you find them, make sure you get to know them enough to check for cases of severe crazy before you decide on a relationship with them.