I’m thinking about my past again

Unfortunately the topics seem to pop up regularly and get me dwelling on stuff. A family friend was talking about their daughter getting bullied and it was really hard to listen to. I felt like such a bad person, I wasn’t strong enough to talk about the things I did and said to people, I just sat there agreeing with her.
I suppose I should be used to it by now, but it’s really triggering for me and is so upsetting.
Some days I feel like I live in fear of my past, I dread bumping into people that I picked on.
However, I do really want to try to turn this around, one day I do hope I’m strong enough to talk about it all, face to face with people, to let people know that you can change.