Silent reflux

I have been struggling to feed my 3 week old.  Poor baby gets so hungry and gets so excited to eat and starts off great but then after an ounce he gets so fussy.  He gets red in the face, gags, thrashes his head back and forth, coughs, grunts and fights the bottle.  However, he's still so hungry he always cries until I give him the bottle back.  He is formula fed, due to my health reasons, and recently switched to enfamil gentlease a week ago.  It seemed to help initially but doesn't seem to be any help now.  He's better at eating during the day bc I think there are more distractions. However, around 5:00 in the evening the craziness with feeding starts. I feel terrible for him and know he's in pain and I don't know what to do.  We see his pediatrician on Wednesday but he's a pretty passive.  I have been doing my research and it really sounds like he has silent reflux.  I give him gripe water and it seems to help a little but doesn't take it away.  Any other moms have similar problems and what has helped?