It sounds like the regret you have is weighing heavily on you. That's a hard thing to hold.

I apologize if this isn't what you need and feel free to disregard what I say. What I've done in the past is craft and send apology emails to those I've hurt(and it was appropriate to do so.) I also made sure that I actually had something to apologize for. Oftentimes I feel the need to apologize for and beat myself up over things that I don't need to. Being overly critical of ourselves and going hunting for all the things we've done wrong can cause much hurt.

I hope you're able to have grace with yourself and forgiveness will come to you.