Help with baby’s feeding please

Hi since she was 3 weeks old my now current 2 month old has been struggling with feeding we have seen a speech therapist, midwife,paediatrician,gp, nurses and pretty much anyone else you can think of we also tried 4 different bottle brands and flows we found one she’s doing okay with which is currently the pigeon bottle but theirs still times where she will turn her head away and cry because of hunger and suck in her hands viciously and look for milk with her mouth feeding her takes 1-2 hours and she’s dropped percentiles since birth sometimes she’ll have good days where she’ll drink upto 500ml and other times she will only take 300ml for the entire day and she stayed at the hospital due to dehydration just for 2 weeks recently because she just denied every bottle and they had to have her tube fed till she could atleast take an 80ml bottle on her own the hospital didn’t want to send us home with the feeding tube but we are still struggling with her feeding and don’t know what to do and idk if it will get any better also they can’t find anything physically wrong with her she smiles and is very alert and babbles and they have run all sorts of tests