TW: The guy (25M) I was seeing forcefully penetrated even after I (23F) said NO 20+ times. I feel traumatized 5 months later. How to feel better?

It was our third date. I was on my period and I’ve never been comfortable with period sex. I really liked the guy, he seemed very empathetic, caring, respectful and consistent for over a month. He had issues opening up emotionally (I believe he is a dismissive avoidant, exhibited all the traits) and I didn’t think too much about it because everything else was perfect. He came over to my place after we had dinner and I had no intentions of having sex with him as I was on my period. I was very attracted to him and we made out for a long time on our second date but I just didn’t want to do it. I need emotional safety before I can be physically intimate with someone due to past trauma of being in a narcissistic abusive relationship. He seemed very genuine before but on that day it felt like he was a completely different person. When I said NO he said NO back to me. He is huge and I couldn’t overpower him. I said NO multiple times and he said that he will not penetrate but he did. He lied. Even though I looked at him in the eye and said that I don’t want to do it. He forced himself, it hurt a lot. He acted like everything was okay and I just couldn’t speak. I had a panic attack that night and had a huge mental breakdown. When I reached out to talk to him about it, he said that he was traveling for the long weekend. He never addressed this and acted like everything is okay. I met him again but couldn’t bring this up. I broke up with him. I’m completely over him, but I guess I’m still not over the situation. I was reading some news related to sexual assault and I feel so triggered again and can’t stop crying. It feels like he was a monster. My brain can’t comprehend how someone who seems so pure can do this. I have signed up for therapy. Any advice is appreciated.