I've intentionally hurt people in my past and while I couldn't go back and undo my mistakes, I could change who I was. And I did. I think it takes someone breaking your heart like never before to truly change you. You can't change the person you were or the things you did. Don't re-live the things you wish you wouldn't have done. Don't talk about it. Instead change who you are and live like no one would believe you actually did those horrible things. Be who you want to be.
Choosing Buddhism was hard at first because it meant a complete overhaul from the inside out, to call myself out on bullshit, to know only I make myself suffer But it was the BEST thing I ever did for ME