Antireflux treatment side effects - burning tongue and cramps - HELP

Hi! I am a 35-years-old female and have GERD due to LES weakness and esophageal hypotony, both caused by my autoimmune desease: spondyloarthropathy HLA B27 positive. In the past I was able to control my reflux flare-ups assuming Carafate and 20mg of Prilosec or Protonix from time to time, which helped without causing any significant side effetcs.
After some time both medicines started causing bad stomach cramps.

I have had a reflux flare up for 6 months now causing me a mild esophageal inflamation (inflammation),Schatzky ring and a small hiatus hernia. I've had upper endoscopy, Ph measurment test and manometry till now.
I have tried all different kinds of medicines: 4 PPIs: Nexium, Prevacid, Aciphex, Protonix; 2 H2blockers: Zantac and Pepcid; 3 others: Gaviscon, Magnesium and Riopan. I couldn't take any of these more than a few days (from 1 to 13 days) because of their side effects.

The 2 bad side effects I've most often had are:
worsened IBS - bad abdominal cramps (caused by Nexium and Zantac)
slightly red and severely burning tongue on boards and tip (caused by Prevacid, Zantac, Protonix, Pepcid, Riopan).

Nobody knows why my tongue starts to burn only after a few pills of ANY antireflux medicine. Doctors think I should have some allergy tests done because I may be allergic to their ingredients. Perhaps. However, I think it's a reaction connected to the effects these medicines have on acid.
I started having bad side effects from the first medicine I tried: I took Nexium 20mg for 11 days and it caused me temperature, muscle aches and bad abdominal cramps. As far as I know, this are Nexium side effects. However, every single medicine I took after it caused a severely burning tongue.

What do you think it may be? I appreciate some suggestions. THANKS!