Sorry that you feel like you are being treated so badly cyclebreaker123. It sounds like you are talking about splitting behavior. I know it seems very personal, but it is rarely that your pwBPD acts this way on purpose because they need someone to beat up on. It comes from their inabilty to see gray areas in a person so the person either must be all good or all bad. When they are good, they are the best thing in the world to the pwBPD. When they are all bad, the pwBPD sees them as an enemy.
YOu can read a little more about this here:
How a Borderline Relationship Evolves