I whole-heartedly vote that she's nuts and you should cut your losses and get out. Have some sex for the last time, and then part ways. Even if you want to blame stress, it shouldn't make a person that insane and self-loathing. If it does, there are other issues and it's not a person with whom you're compatible for a relationship.
Get out while you don't have kids together, and move along. Good luck.
