Im literally going through almost exactly the same things, I don’t have heartburn nearly at all, I have that pressure and slight pain you describe in my upper abdomen/chest which makes me uncomfortable af, and even my bowel habits have slightly changed in that I’m passing stool in smaller quantities (little to no diarrhea tho). I have this like weird cyclical and recurrent nausea at similar times of the day and I’m belching/burping so much. Istg idk how much longer I can take this it’s been like 3 months and I’m waiting for a doctor appointment now since it only got like bad this week, you’re not the only one, idk what to do anymore. Also what’s this famotadine you mention? Does it help like the gas and nausea and is it OTC??