Hello and thank you for contacting me.
Your girlfriend appears to be quite manipulative, a common trait of a bpd. She seems to have put her hooks on you for good. This however only happens because for some reason you allow it to happen. You can not change her but you can explore, understand and ultimately change the way you respond to her. Before you can make any decisions you need to understand what is making you so vulnerable against her, almost dependent on her. Could it be certain experiences or relationships you had with your immediate family?Do you find common traits of your girlfriend's personality in your family members, possibly parents?There seems to be a need to for you to relate to this woman although you body and mind tells you strongly otherwise. Your mind tells you that her ways are not appropriate, are not normal and you feel co erced. However, when you are away, you feel strongly drawn back to her, like she is a magnet. This has nothing to do with her but with you. You need to explore your deeper needs that somehow are met through this girl. You are definitely getting something from her and you have not realize dit. However, whatever this may be, it is not healthy for you and you know it.
If you feel that you usually get involved with people with traits and personalities like hers, then this is a pattern and it definitely indicates certain difficulties that you may have. In this case, I would strongly recommend that you sought long term psychotherapy, psychodynamic or psychoanalytical psychotherapy, that would give you the chance to work on a deeper level, on a personality level, exploring early relationships and how these have affected you.
I am sure that you are aware that as other people may have told you that this relationships is no good for you. However, I don't think that this may tell you a lot as I am sure you have your own reasons for being with her, although you may not be realizing it.
Please feel free to share any thoughts on this.
All the best