Healing how to feel confident

I had a boyfriend he slammed my head into car and took off my seatbelt speeding. It was when I had my learners permit, I haven't learned how to drive after he was supposed to show me.

How do I feel confident he would say I was fat, ugly that people looked at me because of that but I was 100lbs 5'4 I don't get it, I was asked to do modeling but I wasn't 5'8

I felt insecure about myself I look to the ground when I walk and wear clothes that cover all of me.

How do I hold my head up not care what anyone thinks? How do I feel confident? How do I get assertive? How do I get over all the things he said? How do I start driving any tips