The absolute best lesson I learned in life was that you can’t control how people are going to treat you, you can only control how you react to it. And not everyone who hurt you cares. So why should you care? You have to just let it go and move on. It’s hard, but when you finally learn, life will get so much easier.
Obsessing over what someone said or did to you will bring you nothing but harm, especially if that said person doesn’t even care that they hurt you to begin with. You don’t have to forgive, but you have to forget & let go. And the easiest way to letting go is to forgive. Not for anyone else, just for yourself. And you don’t even have to tell them about it. Just do it for yourself.