I need help !! Feeling defeated! 😓

So my lo is 10 days and old. We ebf for the first 5 days and after lots of trial and error she was latching and sucking fairly well. Day 5 she had lost 13% of body weight and very jaundice. We were admitted back to hospital and told we needed to bottle feed. Now I am trying to bf again but we still have to supplement, however I make enough milk I only use formula every other day. Problem: she will not latch and the rare times she does she sucks 3-5 times then gives up! What do I do?? How do I reteach her? How do I get her to suck?? Please help I'm so frustrated and want to do what's best for my baby!!