Something I don't broadcast often on this site, is that I used to be a real piece. When I say that, I mean I routinely committed petty crime and a couple felonies. I will never go into what they were, nor will I discuss why I was doing it in the first place (at least not in the foreseeable future). Either way, people got hurt because of what I did, on several occasions. Something a friend told me, not long after I quit doing the things I was doing, was that I needed to find some way to forgive what I had done. Otherwise, all of the 'sorry's' I could give would mean nothing. I couldn't forgive who I was at that time. I wasn't worth forgiveness, not by a long shot. Well, it sent me on a journey to figure out how the hell I could ever forgive what I had done and who I had become. The fact is, I couldn't forgive that person and had no intention to do so. I came to the conclusion that in order to be worth forgiveness, I had to change the parts of me I deemed unworthy. That's exactly what I started doing and have been doing it since. Every day I work to make myself a better person, I forgive myself that much more. It's not something you can force, it's something that (for me) came with time and positive change.
Anyway, there's my elongated answer for you. I hope your own journey provides a bit of self-worth. Just know that, yes, it is possible; but it is also difficult and worth it in the end to put forth the effort.