I want my girlfriend to break up with me
Why do you want her to break up with you?
All in all, I think she is a bad person for me
It sounds like you are in a tough situation being in a relationship with someone that is bad for you. But, it will be easier and more honest if you end things with her rather than forcing her to end the relationship.
Oh my god, what she did was unforgivable. I'm going to break up with her anyway. I just want her to do it so I do not have to.
I think it is okay to break up with someone that is not right for you. You do need to be mature and have a talk about it in a timely manner.