What do I do? I am feeling so bad about my past and now i wanna fix it?

Sometimes there is not much that we can do to fix what has happened. The best you can do is make it as obvious as possible that you are sorry and wish to apologize, and then move on. It will be up to the others to forgive you and to move on in their lives. If they are not willing to forgive, that is their problem. Do all you can do make up (within reason, don't go overboard, just simply let them know you're sorry and wish to apologize), and then move on.