I used to be in what I now understand was an abusive relationship, and I stayed longer than I should have, because I cared about that person and all of their good qualities didn't line up with the whole narrative about abusers being worthless scum that didn't care about their partners. Everyone is capable of doing horrendous things after dealing with too much or too long. I believe that abuse is a result of people not breaking up when they should have long ago. It sounds like she has been emotionally abusive to you for a long time. You say you feel weak for not being able to take it, but refusing to be with her anymore when that behavior started would have been the strong thing to do then, and it's the strong thing to do now. If you can, seek therapy, as we usually find ourselves in these situations repeatedly, because we think dealing with this stuff is normal and it's not. This is not likely the first time you've been in an abusive relationship, and it takes a lot of work to make sure it's not your last.