If you really want to get better. Seek help. Be honest with your therapist, or else there is no point.
As far as fixing past wrongs is concerned. Nope, sorry mate. Life doesn't work that way. You could single handedly cure cancer, end world hunger and invent the longer lasting light bulb. The people in your life who you have hurt, will still be hurt.
As for being a hero. You really want to be hero? Or are you looking for a positive celebrity?
Hero's happen every day to someone. Whether it be helping out at a homeless shelter or soup kitchen. Volunteer at a school, hospitals, care homes, etc, etc. Make a positive impact in people's lives. Will anyone ever point you out of a crowd and say "Hey, there's whats-his-name. He does (insert amazing feat)? Probably not.
But you'll have done some real good. That is all that matters.