I'm sorry your girlfriend is in such a circumstance and environment. That must be very hard for her and terrible for you to watch. I think what you are feeling is natural. I have 2 teenage sons and I've been ignited in similar ways when I felt it necessary to protect them from threat. Do your best not to act in aggression, but if you need to protect someone it's a defensive situation. Good luck and may you all stay safe and unharmed.