I want to echo others when I say: Accuray, your posts are always tremendously helpful. They are especially helpful for people going through an A (like Luv and myself), but they're also great for anybody generally dealing with a nutty, spiteful WAS. I've saved so many of your posts, it's unreal!
As for Luv: I hear you, man. My W used to be wonderfully loving, too, but since the A, all that's disappeared. The important thing to realize is that it has way more to do with her than it does you. Think of it this way: what she's doing is so hurtful and unlike herself that she actually has to change into an entirely different person to feel like it's okay!
I would suggest trying to find the documentary about the Stanford Prison Project for perspective. Total proof that people can change entire identities given certain circumstances.
It's very tempting at this point to place all the blame on yourself, but don't make that mistake. Your W is in a place where she would love it if you'd shoulder all of the blame and she didn't have to take any.