help !!!!!!!!!!!!!!!!

I posted a couple of days ago regarding my son and having severe reflux. He started prevacid 4 days ago 7.5 mg which I think is too low. And the whole day he has cried. I left him with my mother 4 the last hour and she said he screamed in such pain for the whole hour i mean my mom was a nervous wreck. I honestley don’t know what to do I mean he is in extreme pain i feel as though the medication is not wworking. I just wish there was something I could do to help him. I feel like calling the doctor and asking for something else but the doctor was kind of ticked off that I got them to get the reflux test stat. I just was not going to wait two more weeks while my son suffered in pain. I feel like these doctors down grade this like its nothing. I sorry everyone I just need to vent I am so stressed i have had no sleep and I have 3 other children to take care of what do I do?????? Me and my husband are going to give him a little while to see if he will calm down i just gave him the med. If not i am off to the er to see if they can give him something else to relieve his pain. Poor baby…. Does anyone know of something else to ask for that may work better..