How can I disregard my past?

I know who I am right now, an over-emotional little priss with massive social retardation and no confidence. I swear I'm done with that, but I've carried this scum bag parasite around with me all my life. How can I just excise it from my being as long as I have memories of the ridiculous pathetic episodes of my life? I mean how do I get over half this sh*t, it has become my identity. How do I say no that was not me that was some disgusting thing dwelling inside of me that had to die off? I guess what I'm saying is I can't move forward if I continue to be myself.