7 week Old Infant GERD and Sleep Disturbances

My 7 week old boy was born at 39 weeks via c section and spent 10 days in NICU for respiratory distress; treated with antibiotics for pnemonia. He came home on a routine of wake/eat/awake/sleep. Shortly after his difficulty sleeping began. He started skipping naps despite great effort to put him down. At night he grunts, pushes, makes very loud noises, and awakens frequently from gas and reflux. He is exclusively breastfed and I eat NO allergens at all (just organic fruits, veg, chicken, turkey, and potatoes). His bowel movements are fairly frequent and were yellow and seedy with no odor as to be expected... but now can be greenish and sometimes more watery. They also started to smell and have more gas. The reflux worsened and I started on zantac after the usual remedies would not work. I just came across this info on Nat Phos 6 and would like to know what dose would be good and if there are any other remedies you would recommend to help with gas and sleep. He seems to be rather sensitive and awakens easily/ responds to stimuli easy. And information is greatly appreciated.