B, I don't know this chick... for all we know she may be a fine person deep inside. BUT, seems the shit she's put you thru is unwarrented. There comes a time where you have to walk away. She is an adult, even though you state she has mental issues... she can make certain decisions and should be held accountable for them. YOU deserve better than this B, why over and over subject yourself to this?
I haven't quite kept up with the situation, read bits and pieces... and what she has done isn't right. Move on, hard to do easy to say I KNOW, but this relationship isn't healthy sugar.