IT's a terrible position to be in.
All I can say is, you will be beating yourself over the head over and over and over again , she will not change because you think she should, she won't even change for herself, she will keep doing what she is doing until she and only she sees it as a problem, and then she will change her mind again sounds like she is not even close.
There is no thing you can say or do that will change it. Even threatening to leave will be met with more verbal abuse, it's a no win situation for you at this point becasue she thinks she is having fun.
2 years is a long time to be dealing with it, some people deal with it a lot longer than that. I feel your pain,
, it's agonizingly difficult to move away, it hurts alot.
The only thing that is infront of you is your life, you have to love yourself enough to know that sometimes the most difficult thing to do is what has to be done for your own happiness. After all I have allowed myself to be put through the only thing I can say is Run, run far and run fast, because you deserve to be content. Wishing you all the best, love to you K