How do I forget/move past it ?

My husband cheated and it was about a year later and I cheated too and then he cheated again and it was with someone I (kinda new just saw her a few times at party’s ) I got on his phone one day a saw that he had pictures of her and text between them and he was still sleeping and I was upset so I was just playing music and he woke up and saw that I was upset and he said “did you really think I would not get even” so I asked him why she sent him the pictures and he said oh I fucked her so I got so mad and upset I went up stairs I wanted to leave so bad but it was like 3 in the morning and I had no wear to go so I just stay in my room away from him and then I got his phone a different day and saw a video of her giving him head in “his” room (I don’t go in there any more unless I have to) so that just pissed me off more I forgave him for it and just tried to move on with my life but I can’t get the image out of my head and the thoughts of it and I just get upset sometimes and I just want to fight with him about it all over again I just don’t know how to move forward and past it