Speaking from experience
I read your description of all that going through your thinking, your regimen of pills and potions, observations, expectations and so on and it reminds me of what I go through when I am trying to solve my problems BUT create some more problems in doing so --
You do realize there is an emotional component to all of this whereby your stomach, gut, swallowing, etc are affected by the mind's reinforcement of the message, "we have a problem, oh no!" So that at least, you have another nagging component of worry, but more than that, stress responses that are then adopted by your systems -- all very reversable.
I am not in a place to comment much on your medical situation. You might have really needed those PPIs... You might well benefit from letting your natural HCL do its job, on the other hand. I believe in that and have benefitted from no longer taking Nexium. I also read some things concerning gut and lower GI, that make me wonder about possible allergic responses to grains or glutens... I am finding for now I am far better off eating alkaline mainly, and avoiding wheat as far as bloating, regularity, and cutting way down on gas.... etc.....
But mainly, I can read the stress and obsession... that's where I want to suggest that between you and either your trad. doctor or a trusted naturopath who is not too far out, has a good pragmatic sense of digestion and holistic outlook................ you make sure you are on the right path and then do what you MINIMALLY need to do, don't expect changes by tomorrow night or even two weeks from today. Make sure you are pared down to the essential supps you really need for your goals, and don't be gobblin' pills all day long, remember it can be a ritual to attempt calming anxiety and worry over health! And that's a trap, remember to sidestep.. Relax today, take care. -- Brien