We went straight to Prevacid, had a great doctor. I tried to wean him several times off it, and finally did successfully at 9 months. I think we always question "is it my diet, is it really reflux, is it just his age" etc. The Prevacid is not super easy(although not too hard) to administer unless your insurance will pay for a compounding pharmacy. It comes in a powder that you mix with a little water and give immediately with a little syringe.
What I found out many months later is that it is me with the soy intolerance. My body's reaction to the soy may have been what caused so many of our problems.
Cassie, just get him to where he is feeling better. Then add back either soy or milk and see how he does. The Prevacid takes a little bit to work, but wow what a different baby I had. He slept so much better and I did too, makes life so much easier to deal with!