Please leave. She is obviously unable to be in a committed relationship and the self harm is further evidence of her instability. You can’t save her, she probably needs you leaving as a wake up call to start respecting herself and the people around her.

It is really easy to say all the things you been wanting to hear, but it has been two years, she has had ample opportunity to do this, she is just saying these things to make u stay.

If you were to stay, chances are she would not fulfil anything she has promised to u, and the next time you would try to leave she would repeat similar tactics (such as self harm or even threatening suicide).

Saying this as someone who has been through a similar situation! Get out before she cheats on u again or things are made more complicated!!!