my current situation..(long)

Hi moms. I'm currently feeling hopeless with my LO's sleeping situation. He's soon to be 4 months old and still needs to be rocked/bounced/held to sleep. He'll only sleep long periods of time if I'm holding him or if he's laying on me. He will sleep if I lay him in the bed (we co sleep) sometimes. But he moves around A LOT. I have to pat him and shh him to make sure he stays asleep. He has SILENT reflux. Which means his milk comes up but doesn't come out.. this causes him to be uncomfortable, gag, and squirm around in his sleep a lot too. I've tried elevating him and it doesn't seem to help..again it only helps when he sleeps on me on his stomach. 
He still eats every 2-3 hours..he only eats about 3-4 oz he can never drink more..he still wakes up every 2-3 hours as well.. I've tried laying him down when he's drowsy but it never works he fusses and cries until I pick him up and rock him to sleep.. I've tried white noise it only helps a little bit..I've tried swings, rock n play, swaddles, nothing seems to help.. even if he's laying on me he will still wake up after 2-3 hours of sleep..sometimes the milk coming back up is what wakes him because he's gagging..he's on Zantac which helps with the burning but unfortunately doesn't stop the milk from coming up..I'm exhausted and he's getting bigger..and heavier..he's already almost 16lbs and I'm feeling like it's never going to change..I feel like every month I hope it'll be the month his reflux gets better and that he will magically sleep through the night but each month is the change..some months it seems to be getting worse..he's been like this since before he was 1 month old.. I'm just sitting here thinking what if he's 6 months and it's still the same..or 9 months..or 1 year old and everything is the same..will I ever be able to sleep? Will he ever be able to sleep comfortably and through the night? I'm just feeling very overwhelmed and exhausted..not to mention his lack of sleep also affects his mood and makes him a lot more fussy sometimes..idk what to do..I keep telling myself to wait it out but at this point I feel like it's not going to change..