How Can I Have More Confidence?

I have a very low self esteem. And I mean low. I get very anxious around people even if it's just one person talking to me. I had an abortion a couple years ago and since then I've been carrying around so much shame that I can no longer interact with other ppl. I can't look at ppl in the eye. Please let me know some tips on how I can be more confident. also if you have similar experiences please share. 
Ps I grew up in a super religious household. I was always taught abortion is the worse sin one can commit. 😢 no one forced me to have the abortion. It was my choice.