I can understand why you are upset. Your girlfriend's behavior is excessive and sounds like her thinking is almost paranoid. You have tried talking to her and told her that this may break the two of you up and yet nothing has changed, I am afraid there is not much more you can do. You will have to draw a definite line, respectfully XXXXX XXXXX that she either gets professional help or the relationship is done. Give a time frame, 2 weeks? 1 month? for her to make and keep an appointment with a therapist. Tell her you will go with her if she wants. Stick with your decision. If she doesn't get help, she is not going to change. You either accept the relationship as it is or move on. This is a tough decision but you deserve a healthy, fun relationship.