How do you deal with old memories that still hurt when your relationship is good now? F31 M40

My boyfriend and I had a really rough period about two years ago. During that time, he treated me badly and said/did things that really hurt me. I brought it up to him a few years ago, but he said he didn’t remember any of it and insisted that he would never do something like that.
He did say, “If I did that, then I’m sorry,” but that was basically where the conversation ended. I never really got a genuine apology because, from his perspective, he doesn’t remember doing those things in the first place.
The thing is, our relationship is really good now. We get along really well, and I genuinely feel happy with him. But every now and then, those old memories come back and I still feel hurt by them.
I don’t really know what to do with those feelings. Bringing it up again feels pointless because if he still doesn’t remember, I’ll probably just get the same “I’m sorry if I did that” kind of apology, and honestly, that wouldn’t mean much to me.
At the same time, I wonder if I’m supposed to just let it go because it happened years ago and our relationship is good now.
Has anyone been in a similar situation? How did you deal with old hurt that was never really acknowledged or apologized for?

TL;DR: My boyfriend and I had a really bad period a few years ago, and some of the things he said and did still hurt me. He doesn’t remember them and only said, “If I did that, I’m sorry.” Our relationship is really good now, but those memories still come back sometimes. I don’t know whether I should bring it up again or just let it go.