I used to have this problem.
I would remember something selfish or stupid I did when I was younger and the memory would hurt. Literally. I don’t know if it was actual physical pain or just pain in my mind, but it would hurt.
I would be eating dinner or taking a shower and I would feel the memory approaching like a tidal wave. There was no way I could stop it. All I could do was brace myself and wait until the memory would go away.