Need advice, help. :(

I was sexual assaulted almost two years ago. I’ve managed to do a lot of healing with love, patience, self care, painting etc. A night ago was the first time I had sex with my very trustworthy, loving boyfriend (whom I’ve never told about my sexual assault😬) and it went very well, I was comfortable and not anxious or triggered at all. When we were done we cuddled for a bit then all these bad feelings started flooding in. I felt gross and dirty like I had just done something bad. He wanted to get cleaned up and I insisted on taking a shower by myself. I got in and just cried, I felt horrible, it took me back to how I felt two years ago which I thought was long gone. The sex was great in the moment but now I just feel so horrible about it. I don’t know how to tell my boyfriend without making him feel bad. I don’t want him to feel like he did something wrong. He’s such a positive, happy person I don’t want to pollute/or hurt him with my pain. I’m also scared how he’s going to react considering I’ve never told him I’ve been sexually assaulted before. I’m also just confused on why I feel this way, I thought I was past all the pain and trauma.

This is just bringing back a lot of old feelings. I’m so upset that this even happened to me and that I even have to go through this😔. I should be able to have sex with my boyfriend and feel great.

I hope it’s not inappropriate to put this topic in this group. I posted this in another group and no one answered so I thought to put it in a different group. I’m just really struggling right now, I haven’t felt the same since that night. I don’t know how to express this to my boyfriend and I don’t have anyone to talk to about it.