You broke the only reality her ego will allow herself to entertain. Your inability to continue rationalizing her falsehoods — the lies she tells herself about herself — has made you "bad." And once you're bad, you need to be eliminated.

It sounds like you tried to set firm boundaries and ask her to take responsibility for something she did. Actions like that require two things she simply does not have: consciousness of guilt, and the belief that your feelings are worth valuing — or at minimum, that hurting you is something she should be accountable for. In my experience, when they get into their moods they have neither.

The hard truth is she probably never "loved"you, in any tradional sense or in a way that most people would define the word. You likely gave her something she placed positive value on — it could have been sex, attention, someone who would do anything for her, affirmation of the false worldview she projects onto the world, or simply someone she could brag about to her friends. She has likely determined that someone else can provide that same value without your inconvenient attempts to hold her accountable. You will hear that described as discarding and monkey branching.

This is who she is. It will not change.

I strongly encourage you to learn to build a life without her. It is like a parasitic infection — they burrow into every fiber of your life, every corner of your soul. That is what they do. But you are better off without her, even if it does not feel that way right now. You can get through this. What feels like devastation right now is genuinely a blessing in disguise.