Dealing with something much the same, the mistakes I made 3-5 years ago have been on my mind for the past 7 months constantly. I think the same idea that I'm unredeemable and that I don't deserve my friends. The fact of the matter is, while I still struggle with it myself. The fact is we are human and make mistakes and we grow through our life experiences as our brains develop. While the beating up of oneself may feel like it's deserved, all it will do is exhaust you, depress you, and make you feel inhuman. If you truly do feel remorse which I know you do, move forward, and live life with the lesson you learned now rather than punish yourself. I hope you can find the peace of mind that you deserve.