Help a Mama Out SOS

So I’m calling out to all Mamas with an SOS to breastfeeding my babe. She is coming up to 4 weeks old and she isn’t breastfeeding well at all. Since day one she had an amazing latch but kept pulling off because of lack of flow. She lost weight and became jaundice so I fed her breastmilk from a bottle. Since then she has refused the boob. I keep trying her and she keeps freaking out. I have bought a nipple shield and she did great and took to it. Now she won’t take it at all. I’m so lost and so devastated. How do I get her back in the breast?

I do put her on the breast and she latched and sucks but pulls off within minutes and screams and cries because she has to work for the milk and refuses to...

Please help! Any tips, tricks anything. I will try anything to get her to stay on the breast. Is it too late??? Am I now a lost cause???

Thank you mamas!!