I think your honesty in sharing this is important and really positive.
I said some pretty rotten things when I was younger, I think about it a lot too, and it can be hard to not get stuck on it. I had a lot of friends and peers who were doing the same then. All of the ones I'm still in touch with have grown out of it and talk to each other sometimes about how we used to be. I think we can condemn our past actions without also condemning who we are right now. People can grow a lot, and it sounds like you have in a really great way. We can recognize that even if we're the same person that did something we regret, we may have a completely different perspective on it now, and might know we would never repeat it.
Personally, I don't usually feel the need to confess or discuss how I was to people that history isn't immediately relevant to. I think with anxiety and guilt can come a need for penance, but I think most people we meet aren't interested in holding us accountable for our whole past, just who we are right now and who we will be going forward.