I can't stop comparing myself to my boyfriend's ex
My boyfriend was in a long term relationship right before we started going out (five years.) The relationship had its ups and downs and was overall very toxic. He is much more experienced than me in many ways as he is somewhat older than me. I've always struggled with retroactive jealousy to some extent in all of my relationships but I learned to sort of deal with it. My boyfriend and I openly go through each other's phone every once in a while as we both have had some not so great relationships. A few days ago, I checked his camera roll and ended up finding a bunch of photos of his ex including videos of them being intimate. Admittedly I freaked out on him. One of the videos was from when him and I were already talking romantically. Seeing it actually in action brought it to a whole new level.
He eventually was able to calm me down but it hasn't left my thoughts since. I catch myself trying to mimic the things I saw her doing when we're intimate and I'm disgusted in myself. It's even at the point where he has called me out for initiating sex way more than usual or just straight up not acting like myself.
Part of me is scared that because his ex and the things they did together is such a big topic between us right now that he's also thinking about her. I wonder if he compares me to her as well.
I feel like I should make it clear that my boyfriend is very reassuring and honestly struggles with a lot of the same things I do so he gets it. But I know it is starting to annoy him and we have been arguing way more. I can't think of him without thinking of her. I feel gross knowing the same hands that are on me have also been on her.
I'm scared I will spiral like I have in the past and ruin the relationship due to the mere fact that I saw what I saw. I know none of it is his fault and I've come to accept I can't be mad at people for living a life but literally seeing it is driving me insane. I can't sleep at all and I feel nauseous the second I think about it.