My GI Symptoms Have Been Increasing - What Could It Be?

Hey everyone! I've been having increased GI symptoms recently and I was hoping someone might know what's going on. This will be long, sorry in advance. Quick background: diagnosed with POTS and multiple other conditions starting spring 2021 after a virus. Had moderate nausea and abdominal pain with eating from POTS, and diagnosed with mild chronic erosive gastritis. It wasn't until I got a cold/upper respiratory virus, (twice negative tests for Covid), last September that my GI symptoms progressively have been getting worse. Ruled out any medications causing it. Started as sore throats after eating dinner most nights, but I thought I was just still recovering from the virus. Then led to heartburn laying down at night, and now progressed to very constant throughout the day. It just started one day and has progressed since, and I've never had any acid reflux issues. Did full GI tests back in 2021 and only showed the erosions in my stomach, everything else was normal but obviously that may have changed since then. Doesn't matter what I eat or drink I will get bad heartburn, chest pain, sore throat, acid coming back up my throat, sore taste in mouth, bad breath from acid, burning feeling in stomach, sharp stomach pains, nausea feeling like I'm close to throwing up, and pain if I press on the top part of my stomach lightly. This doesn't only happen after eating also, often I will take up with heartburn and chest pain even if I haven't eaten since the evening before. No vomiting. And as time goes on, my appetite keeps decreasing. I don't feel hungry after a few bites of food, and feel really full/bloated majority of the day. I've lost a little weight from lack of appetite, but nothing worrisome yet. Zero relief with OTC antacids (pepto bismol, TUMS, pepcid). Tried prescription PPI (omeprazole) for 6 weeks on two different dosages with no relief. Did a 2-week trial of Carafate 3x daily with no relief. The only things I can think of are GERD or some type of delayed gastric emptying, but when I saw my GI initially she didn't mention either of these and said she wouldn't consider doing another endoscopy for 6-8 months after. Any ideas about what this could be or ways for pain relief? I'm scared I will do repeat GI tests and it all comes back normal.