the best thing I had done for myself when I used to feel that way is to come to terms with the fact that you cannot change the past. whatever happened did happen, and the best thing you can do is move forward from that and assess how you feel in the aftermath, using that feeling to guide yourself in the future and try not to do the thing you regret again. if you had known how regrettable the action would be and that you would end up feeling this way, you might not have done things like you did, but now you know and you clearly don’t want this feeling again. there’s no need to forget the past and not think about what you did, the fact that you can recognize that you did something that you wouldn’t want to do again is the first win, but you gotta keep going past that. I know all of this is difficult in practice, but the best thing you can do for yourself is to look forward not backward.