Struggling with Sexual Trauma in a Relationship

This is gonna be hard and long so just try an stick with me here :/ I went through a lot of sexual abuse as a child let’s start with that, so my entire life I’ve had a really messed up relationship with sex and the thought of having sex I think I use sex as a way of self harm but I’m not sure I could consider it that anyways tho moving on I dated this guy for about 2 and a half years and he was kinda understanding of the whole sex thing but we still had some problems We’ll we ended up breaking up about 6 months ago but since then have tried to reconnect with each other He ended up telling me he had sex with some other girl etc etc etc but that really upset me (even tho we weren’t together, we had been together for years and he didn’t even wait 6 months before finding someone new?) he did cheat on me during our relationship tho and said it was because I didn’t have sex with him often enough Now that I know all that information on top of my already really fucked up perception of sex I just really don’t think I’m able to be with him There’s nothing wrong with him other than the whole sex thing He keeps telling me I just need to get over it because not everyone takes sex as serious as I do but I just don’t know how I was already having a problem with my sex life and that made it a whole lot worse So now I’m in this never ending cycle of wanting to be with him because we’ve had so many good memories but also scared to be with him because I’m not ready to have sex with him again and if I don’t I fear he might cheat on me