The general advice as Colonel pointed out earlier is you have to leave.
Chojin touched on something though too. In life all the best things that happen to a person happen because they finally made a decision that was hard. It is human nature to be content with the status que because the unknown scares us. This is precisely why you are frozen in a quagmire of indecisiveness. Ultimately you will be compelled to leave, it is inevitable, and if you don't do it now, keep this in mind; eventually, while she is doing bad things now, she will eventually do something much worse to you, it is only a matter of time, so why wait for that shoe to drop? Get out now while it is only this bad before it actually becomes worse (which it will)
Alright, DUR. No more advice, I'm now taking bets as to whether or not the bbw hell troll punches him in the dick when he once again"tries" to break up with her