Originally Posted by
Bewilderd 
it hurts so much that instead of pulling together, caring and showing love, all she can do is hate. Why does she need to act like that? And I also can't help feeling sad for her, she was such a sweet, funny, clever beautiful person once. I feel so sad, so hurt, but in the end I'm also hardening myself, because nothing will change.
I can't tell you why she does it. Is it mental illness, something brought on by alcoholism, chicken or egg?
What I can say is it isn't personal, but you will really have to acknowledge a few things before you can break free.
First, the sweet, funny etc person is gone. Your wishing and expectation will let you down every time you encounter her (and probably makes you sad just thinking about it). You will grieve the loss of that person, but in the long run it will set you free from her. Next time she is hurling insults etc, don't make excuses for her in your mind - really listen, really look at her face and her expressions, is this the person you knew? No.
You will also probably have to accept that you will never know why she targets you. It probably is some misplaced anger on her part (again, not personal), but it's there.
Your best bet is to never be alone with her, always have others around if you must meet. When she is abusing you, don't participate. You never have to JADE - justify, argue, defend or explain yourself.
If you feel you must reply (google 'grey rock) - use short no-meaning answers like - well that's worth thinking about - uh huh, oh, you may be right - well all we can do is carry on, just things like that, memorize them, have them ready.
When she is around or you are forced to talk to her, picture that you are in a "defense bubble" and that everything she says just bounces right off you (sounds silly but it works).