sometimes, even if they don't forgive you, the best and only thing you can do is recognize where you did wrong and move on. we unfortunately cannot erase the past, and somethings cannot be forgiven, but it's ok.
I know that does not bring comfort, but sincerely there are moments we are inevitably bound to, therefore what's left is learning how to live with them.
that doesn't mean you are bad person or that you can't do better. as long as you can acknowledged your flaws and put effort into not repeating your mistake its ok.
some people will hate you, and considering their reasons, they might or not be right. perhaps the key is to consider that they have only been exposed to a minimal part of your personality, maybe you were in a bad day, maybe the issue was a sensitive one for you. I'm sure there are good positive traits about you and those people were surely not exposed to all of them, perhaps not even you know them yet. No one is 100% bad, in the universe there is good in bad, and vice-versa, that also applies to you.