We have to accept our pasts; the wrongs and rights, however it is you see them. You can feel shame or insecure, maybe others will think otherwise, maybe they will agree with you. Accept that there are things you can teach other people, things you can contribute into the collective. Someone out there will find value in your perspective and the experiences you have had. How they respond is up to them.

I am someone who preaches unconditional love and compassion, but I am not someone who has always been like this. Nor do I find it easy to be in such a state. Every time that I find myself outside of my ideals, I bring myself back and remind myself. I accept what I have done and try to make up for my wrongs, but I move on in the state of my ideals with what I can. 

You cannot change your past, not in the way you want to. but you can influence your present, and thus, you can influence your future.