this is who i am and now nothing will change me

This girl I have met, she brings all the good out of me and it puzzles me how she does it. Then I realize what it is. It's her. Something about her makes me feel like I am about to fall. Or turn to liquid. Or burst into flames. I feel even though we are far apart that nothing would keep me from protecting her if I had to. There's something inside of me that wants to make her smile every time something inside that wants her to be happy. Something inside that doesn't want to see her hurt anymore.
She makes me believe that somewhere inside me is a merciful, forgiving person. Somewhere there is a girl who tries to understand what people are going through, who accepts that people do evil things and that desperation leads them to darker places than they ever imagined.  I swear she exists, and she hurts for the repentant girl I see in front of me.
 But then I remember all the bad I use to do. The way I had treated people in the past and I wonder about this girl and wonder how she would like a monster like me. she means a lot to me and if that means I even have to protect her form myself to then I will do that. because I know that myself as a whole cannot be good for long before the bad creeps back in and poisons me again.
Would she understand where I'm coming and how am feeling or will she get scared and flee like most people do? I cant really express my answer because I want this to be her choice.