Barclay and his tummy problems

OK, I just have to write this out and if ANYONE has any advise other than what I'm doing...I'm all ears.

I am beyond frustrated. My poor baby is constantly in horrible pain from acid reflux. He has been off and on Prevacid since he was three weeks old. I've tried to take him off of it about four times but he gets so bad that he cries non stop for hours upon hours and I can't take it.
I have tried probiotics.
I have gotten off of dairy for two months.
I have recently gotten of all gluten.
I have given him his medicine.
I have let him sleep at an incline.
I have let him sleep flat.
I have bathed him. Held him.
I have let him cry it out (not for more than 10 minutes at a time).
I have walked with him.
I have driven him.
I have given up so much and it is still hurting him.

Yesterday was a really awful day as far as crying goes. He used to cry all the time but would without fail sleep in his car seat when we drove. As of a week ago, he hates his car seat and screams blood curling screams every time I put him in it.
Yesterday I kid you not, he screamed for an hour. We pulled over about four times on our way down to Greenville and made sure he was all taken care of, nothing worked. He was shaking and sweating he had cried so much. I have checked the car seat for anything that could be poking him. His straps aren't too tight. But we have to go places, and he has to be in the car seat.

I feel like I have exhausted every possible solution. The pediatrian has recommended Reglan, but there are TONS of lawsuits against them right now and the side effects are pretty major.

I am going to try to EAT some dairy and gluten and see if that works (maybe he just wants cheese like his Mama). He seemed to be WAY worse after stopping the gluten.

I am going to not eat anything spicy this week, although I have to admit I "tested" this a while ago and it didn't seem to phase him.

The next step I feel is to stop nursing...which KILLS me. I love nursing my baby and I think it is the sweetest thing. Not to mention the cheapest thing, most convient thing, most healthy thing...etc. But if it comes between horrible side effects and my selfishness of nursing...I have to choose to stop nursing. Seriously I cry every time I think about it. I was planning on nursing maybe up to a year give or take, and this just makes me sad. I feel like I've given everything I can think of up.

Thankfully, his gas problems are a lot better. I think those are pretty much straightened out as long as I give him Gripe Water every four hours...but this acid thing is AWFUL.

He wakes up because he projectile vomits in the night. I am awakened by a gurgling baby. Yesterday he spit up so much that there were puddles on the floor at the coffee shop we were in. I also feel like I'm feeding him more often than most because he spits up everything he eats. He sometimes (although less lately) spits up clear acid. He cries A LOT during and after feedings.

I've even tried nursing him upright.

What am I doing wrong?

I've heard to try rice cereal, but I have gotten a lot of negative feedback on this.