Uugghhh! Sounds like a pretty bad situation. I could be wrong, but it seems like she has become very manipulative, (threats and hot/cold behavior) and it won't be doing her any favors to indulge it. Either she is going to feel shame/remorse or encouraged and do it again - bad or bad.
If you can, give yourself a nice long break from the whole situation to get your head together. Be prepared for the opposite behavior, (probably with a good dose of lust involved), as this pattern has probably happened in the past and she has probably used sexy/sweet to regain a sort of control.
It sounds like she has more serious problems then a nice commie goblin can solve. Just be very careful not to enable bad behavior, as this will just get worse and worse for both of you.
EDIT: I just hit the back button and noticed this post from a month ago:
"48 hours of fighting with La Principessa led to tearful reconciliations and mutually amazing phone sex. Relationships are weird."
Not a good pattern.