I mean, I get the desire to forget but personally I think it’s better to forgive but not forget since if someone’s shown you that you need to be cautious around them or that they’re willing to do something messed up to you, you need to remember it so you know not to put up with it if it happens a second time and so you’re ready for if they cross the line again. Even if he’s apologized profusely and you’ve forgiven him completely, you should still shouldn’t forget that he did it and how it felt
I’ll be straight up, if what he did made it so you can no longer completely trust him without worrying about if he’s deceiving you, then it’s honestly worth considering whether this relationship is worthwhile in the long run. I was in a relationship where my trust was broken really badly early on, but I stuck with them and tried to force myself to trust them again, but it was impossible. You can’t make yourself trust someone who’s untrustworthy. Once someone shows you who they are, believe them
Even if everything about your relationship other than that is perfect it’s still worth considering because the relationship without trust is doomed to fail it’s just a matter of when. I’m now with someone who‘s never broken my trust or given me a reason to doubt them, and I’m so much happier. The constant stress of worrying if you are being deceived is horrible and even when I was single after we broke up, it was still better than having to feel that way all the time.