You don't need a doctor to do this. The reason your girlfriend is bullying and harassing you is because you have not set boundaries, and it looks like the idea of setting boundaries is so difficult for you, you are actually willing to *pay* someone else to do it. No wonder she is taking charge.
I think you need to learn to be more assertive. Appropriate boundary setting may save your relationship. At the rate you are going now, you are going to wait until your anger and resentment builds to the point of no return, and there will be no way your problem can be repaired.
PS - keep the girls out of your room. Her anxiety about that is justifiable.