Her hooking up with dudes after you broke up is not the same thing as you actually cheating on her twice. You can’t shift the blame for your infidelity onto anyone but yourself. And you being smaller than her doesn’t mean anything. You can still intimidate her and she’s already confessed to you that she’s been triggered in your relationship. If you are serious about working on yourself to make your relationship better then maybe not snarking at your gf for not giving you what you want when you want it would be a good start. Individual therapy for her is something I would definitely start pushing though so she can work through her trauma.