Do you use the mistakes and bad choices from your past to beat yourself up, or do you use the information to better your life and the lives of those around you?
Everyone makes mistakes.
The real question is "Would you make those same mistakes today?" If the answer is no, then take off the hair shirt and forgive yourself. If you need to make restitution to someone, do it. Then move on.
I'm not asking if you're capable of the same bad deeds. Of course, you are. You've proven that. But you're also capable of NOT doing it, as your life now proves. Remember that.
Beating ourselves up with these horrors doesn't remind us what we're capable of as much as lock us up with an abuser who knows where our soft spots are.