Acid Reflux

My 1 month old has been having really bad projectile vomiting. We have taken him to countless pediatricians and nothing seems to be helping. He had an ultrasound done to rule our Pyloric Stenosis and that came back negative. So they said he had acid reflux and told us to give him Enfail A.R which made him throw up even more! So we switched to Similiac Sensitive & that didn't work either. We tried Enfamil gentlease and that failed. So now we are trying Enfamil Prosobee (Soy milk) & he just threw up again 😩 idk what to do! We burp him every 1oz and keep him elevated after every feeding but that has not worked. Who has had this happened & what did you do??