Not wanting to be on this boat........

[Buffet]

I feel like I have been shot about a hundred times but no kill shot yet, it is just torture.
She has absolutely completely convinced herself that I am an a**hole and the end all be all of all of her problems. She is threatening me that she is going to call police and fake abuse tell all of our friends, co-workers, family---that I am a horrible person.
She accused me of having an affair when I confronted her on the evidence that points to her affair. She told me that she has wanted out of the M since day 1.....why do I care anymore? Where is the button that says don't care and how do I get there.
I really need some perspective/help here....