It's hard where you are right now. She can't be trusted to take care of your boy, and your boy isn't safe with her. I sometimes felt like I was in a trap.
I know you know what to do, I know you are thinking about or taking the steps to do it, and I'll just suggest you may need to do it faster than you'd like. The stakes are fairly high, and she cannot be trusted at all.
Take care my friend,
Cyranoak