I know that this is very hard to explain but How does a person Build their confidence?(Sorry it is very long.?

Its wonderful that you have figured out he culprit of your emotional stress. For one, let your past go, live in the present. My father had disowned me when I was a baby dying in the hospital. And I felt worthless so when became older, I slept around alot. So I know how you felt. I was living in a vicious cycle. I had to look myslef in the eye a few times and tell myself I was living and acting wrong. Since you do talk to your father look him in the eye and tell him how you feel. It doesnt matter if he accepts it or not. Face your fear and become a new you. Be proud of your self. And when you feel sad or angry take those feelings and work them out, its better for your body and mind. Just remember be yourself around guys, they dont want to get to know a *****. Just stay positive and enjoy a new you