Slow nipples to slow, medium flow nipples choke her really bad.?

She is 2 months , she went from eating a 4oz bottle at a time to eating 1-2.5 oz every 1 hr or so. She was tested for reflux, she does have a mild case of silent reflux but does better off of medicane and cereal. Shes much gassier now and always falls asleep eating. She is gaining weight. Sh is in the 96th percentile. but she acts so hungry when she starts off and then nothing, shes asleep and is not intrested. Drs say nothing wrong but something had def changed. She ate more at one feeding when she came home from hospital then she does now