I literally can't remember having sex with someone after any kind of breakup or major conflict

So yeah I have a history of abuse and that's probably obvious. But I've been in a lot of therapy since, and in my 30s I feel I have mostly recovered. Maybe you never fully recover from that kind of thing, but I have found myself able to have happy, safe, calm, healthy relationships with people who take good care of me, and treat me with respect. There have been breakups, but they have been normal breakups for normal reasons, where we can part as friends, without any kind of feeling that I was traumatised or seriously wronged by them.

The thing that I've noticed has stuck with me is that after any kind of major falling out, or breakup, my brain basically erases any recollection of me having slept with that person. Like I know that it happened, but my brain turns the sequence of events into a PG-13 movie. I remember how on this day we were on a romantic vacation together, I remember in detail what we talked about, and then that sex happened, but nothing actually specific about it. It's like a fade-to-black. I don't remember what this person looked like without their clothes on, what they felt like, how exactly we did it. It's like I know it happened, but I wasn't there. Like I read a sentence alluding to it in a book.

In some ways this feels like a kind of superpower. For instance I have an ex we'll call A, who was very good to me, and I loved him, but unfortunately it just didn't work out between us and the breakup was very sad. It feels protective to me that it's all a blur to me now. I don't miss "it" because I literally don't remember it. I seem to recall thinking it was good? But the memories of that are gone.

But there are times when it makes me sad. I've been in a stable relationship for 3 years now. Earlier this month, I initiated a painful breakup because it seemed like we just weren't able to come to an agreement about our future plans. However, after about a week we agreed that we really didn't want to throw away what we have, and are back together again. The thing is that as soon as we broke up, all of those memories just self-deleted. It's driving me crazy now and makes me so sad that I can't remember it.

I feel like this is some sort of adaptive mechanism that stops me reliving painful memories. But now even though I am mostly healed, it also stops me reliving joyful memories. I really do with I could remember. I feel grief for those lost memories.