How can I get over what I saw on my Fiances phone?r

My fiancé and I have been having problems with intimacy for several months. Like it hardly ever happens because he says he doesn’t feel good or isn’t in the mood. This was very different from the rest of our relationship because we used to do it allllll the time. I felt like something was going on so I looked through his phone. I honestly didn’t find anything to suggest he’s cheating but I did find videos he made of himself with other girls from before me. This really bothered me because I obviously don’t want to see him with other people but I had asked him to make videos of us several times and he never would. He knows I saw them and he deleted them and said he didn’t even realize they were still on his phone. He promised that he’s going to try harder when it comes to our sex life because he knows my drive is higher than his. So I feel like something good came out of all of this. But my question is, will I ever forget about the things I saw? I feel like those videos are burned into the backs of my eyelids. It makes me sick to stomach. The girls were younger than me (in their 20s) and all had perfect bodies and he was definitely enjoying himself. I’m older and have a very different body from having children and eating too many tacos. I know it’s my fault for looking but that’s not what I was expecting to see and now every time I look at him or close my eyes, that’s all that I see.