3 month old with acid reflux

3 month old boy 15.5 lbs

On set Started at 3 days old. At the hospital he was on similac. He got changed to gerber good start at 3 days old. He began spitting up. He was put back on similac for a few days then changed to another gerber formula this did not rectify his vomiting, they then changed his formula to soy. This did not correct it either. A teaspoon of rice cereal was added to his bottles starting at 4 weeks with this at first he kept more of it down. He then became constipated. When he did poop it was very little and solid balls. He was then taken off the rice at 8 weeks and oatmeal was added to his bottles. About a table spoon is added to every bottle. When he is laying down on his back he is very ridged and stiff. He belly is rock hard. Once he vomits his whole bottle back up he screams. At 4 weeks I noticed that it was not just formula coming back up it was clear and when it would come up he would scream. He was put on Zantac for four weeks. This was stopped last week. The dr said to keep adding the oatmeal and just formula and stop the medicine as it was not working only making the problem worse. I did pick up the Nat Phos 6x. It was administered to his at 6:30 on the 19. And given after every bottle. After the first dose he only spit up maybe on a ounce if that. He was hungry again an hour later ( he normaly goes every 3 to four hours between feedings) He got another 4 oz bottle, and the nat phos 6x after it. He spit up even less and went to sleep there was no screaming of crying. He woke up an hour later and ate another 4 oz bottle, same as before less spit up no screaming or rigidness. Went back to sleep. He had another bottle at 11 pm 1 tablet in water of the Nat phos 6x and spit up very little. He slept all nigh long till 8 am. Woke up for 30 min did not eat and went back to sleep. He didn't wak up till 10 am eat a six ounce bottle, gave him a whole table in water. Then he started spitting up excessively again. maybe 3 oz. All tablets were dissolved in 5ml of boiled water. Went back to 4 oz (all bottles still have 2 teaspoons of oatmeal in them thus far) and one tablet after eating still spitting up. He is ridged again and screaming again after he spits up. (Monday night has been the first night that he has not been up crying most of the night. After every feeding he is kept in an upright position for at least 45 min. When he is laid down on his back he screams pulls his legs up off the surface he is on and become very ridged only after picking him up and 20 minutes will he calm down.) Tuesday morning after he slept all night Monday I was able to lay him down on his back with out him screaming or becoming rigid. He is no longer constipated since being on the otameal and the herbalist said that we should get him off the soy as soon as possible. We were told not to touch the Nat Phos 6x, to put it in the lid and place it in the water from there. We have done that then used a dropper to administer the mixture to him.