I personally think that this is just what she knows. This was the only kind of sex she was having, maybe the only time she ever "finished," and this behaviour was coming from someone who she thought loved her. Most women have a domination/rape fantasy, but it doesn't go nearly this far. She has a lot of issues that she hasn't worked out. You need to show her that she can enjoy sex and that sex can be fun without going this far. I'm not sure she even likes this, but this is what she knows. This is what sex is to her. And this is something that she really needs to work on. And you're going to have to work on it with her if you want to stay with her.
