Abusive ex yet what to do with the positive memories?

My ex was the first person I was ever with intimately, so I just have such cognitive dissonance over the special memories I have of sleeping with someone for the first time. Those were special moments I’m fond of, yet they’re with someone who physically and emotionally abused me later.

Anyone else deal with that, or any advice on how to reconcile? Definitely left with feeling lonely, although I don’t miss him nor wish to ever repeat that ever again.