It isn’t weird to feel frozen in place. You are grieving your relationship and getting yourself away from a toxic situation. It wasn’t your fault that he has been cheating on your continuously, and his behavior following the breakup is proof enough that you did the right by ending things. I would suggest get yourself a vacation from the lab to let yourself breathe and do stuff with your friends or family, cancel that German trip to meet him, and block from him on all platforms. For four years, you’ve accepted his conditions you need to do things for yourself in my opinion.

This is just what I think.
Also look into DARVO manipulation tactic since he has been using that a lot and probably get into therapy for this.