Screaming 15 month old please help?

ok my son has allways slept straight through the night starting the day he was born but for the last week hes been waking up sreaming and crying bloody murder its very high pitched to where it will give you a migrane when he was an infant he was diagnosed with acid reflux and he would have projectile vomiting they tried reglan didnt work then they tried zantac didnt work finally they tried prevcid it helped a little well they wanted him off of it because they figured his body was getting to used to it and therfore it wouldnt work well now hes acting like his stomach hurts again but worse far as pain hes throwing up some but i think thats from the creaming and crying they were talking about surgary on his stomach when he was an infant but thought he may not need it he did good for awhile but now its just worse ive been up 24 hrs now cause he hasnt slept any suggestions i hate seeing him like this could he need the surgary now they thought he may have had pyloris stenosis when he was younger please please help i need to help him so he can sleep as im 7 weeks pregnant and need sleep