hey!
Not sure what you have tried so i will just throw some things out there!!
My DD had some issues when she was about 2 1/2 months just decided she wasnt going to feed from one side
I found that if i did the football hold she would latch on
if i layed down she also would suck so it was just if i sat up and held her

i took her to the chiro and they adjusted her neck and she feed like a trooper after that!
I really hope that helps!!
good luck!