I so agree with valkyrie and uksparkle on this one...
JUST DO IT! Save up your money, find a crib and move out.
Call their bluff. They might be pissed at first but they will get over it..eventually. If they don't that is THEIR problem, not yours!
I went thru the same thing and let me tell ya, moving away was the best damn thing I ever did!
PMing ya! 