Breastfeeding/milk supply issues

Hey ladies. I'm really in need of some support/advice. LO is 8 weeks old... I thought I wanted to bf when she was born, and was doing great pumping/good milk supply. But she was tongue tied and it hurt badly to have her at the breast. I got sick two weeks later, they put me on medicine for about a week, said pump and dump. During this time my milk supply dropped from like 1-3oz during a session to about .25oz. No matter what, i cannot get it back. They clipped her piece under the tongue but it still hurts to bf but i can't pump anything. It feels like she's doomed to formula. I feel like a terrible mother and guilty because i can't give her what she needs...