L.N.
My only advice is to cherish every time that baby latches on to you, and know that eventually, she will transition if you keep trying. I wasn't able to breastfeed any of my boys (although I tried desperately) for longer than a week. They are big and healthy on formula and will grow up just fine, just as your baby will. Give yourself a break from worrying about it and know that you are doing the best you can.