You have gone through a lot and so has your son. It is important with acid reflex that the position of feeding is above 45 degrees or more, almost sitting up. Never lay him on his back when he is feeding because the acid from the stomach goes into the esophagus and causes pain. It sounds like he has issues when he is sleeping too. Raise the head of his crib to a 45-degree angle too so he is not flat on his back. Feeding him 5-6 times a day does help. Feeding that way keeps the stomach acid constant which helps the reflex. If your son can tolerant 6oz every 4-5 hours, then stay with that so he grows and his weight increases at a steady pace. Hope this helps and best of luck.