*TRIGGER WARNING* (sexual assault)

I (F16) was with my boyfriend (M16) earlier, and my parents weren’t home, so he came home with me, and we were making out and then he started like playing with my boobs which was fine, and he started fingering me which was fine, but then he started unbuckling his pants and I freaked out, because last year when I was sexually assaulted, that’s how exactly it started. He knows I was sexually assaulted and I get triggered when something reminds me of the boy that assaulted me. I told him I wasn’t comfortable with going that far right now and he understood but at the same time he was turned on and I get that, but then when I said no he put my hand on his dick outside of his pants, and I said no again, and then he got it. I had a panic attack when he left. I don’t know what to do. I haven’t told him the full story of it because talking about the assault is triggering for me, but I feel like in order for him to fully understand what’s too far and what’s fine I have to tell him what happened. What do you think I should do?

also, I feel bad, because when he was leaving I pretty much yelled at him that when I say no I MEAN no. which was pretty well deserved but at the same time I feel like I should’ve calmly talked to him about it instead of yelling.