Sorry you're struggling so much with this.
I haven't had direct experience with what you're going through, but I dunno, maybe I can help a little bit.
You for sure absolutely are focusing on this to an insanely detailed level. As any of us hypos can tell you, focussing so intently on any symptom will make it worse, so that could, directly or indirectly, be contributing.
I don't know where you live, or what kind of specialist you're about to go see, but I would recommend that you try and see a doctor who has at least a little background in homeopathic medicine, or a homeopathic doctor full stop. Oftentimes, typically Western-trained doctors like to throw meds at patients, especially acid blockers, which tend to just mask symptoms instead of reveal the actual problem. What would help you most now is someone who'll help ween you off your meds and sort of start from scratch. In any case, I bet you will find that after some investigation, that the acid irritation you're feeling is causing less damage than you think. Have you gotten any kind of official diagnosis for what's going on, ever, or have doctors just sort of thrown would-be solutions at you? If all this doctor wants to do is throw another PPI your way, find someone else. PPIs are over-prescribed.
The fact that water makes you feel worse could be a sign that you're suffering from too little acid production (the symptoms of which are the same, paradoxically, as too much acid). Remember, your stomach NEEDS acid to break down food, so the water you're drinking may be washing away what little you have, especially if you've been taking acid reducing or blocking meds for some time. Don't be so afraid of the burning sensation that you inadvertently make it worse. Remember, the actual damage to your esophagus, if any, is still quite minimal, so if things are burning, don't be so quick to try and alleviate it. Let it burn, as uncomfortable as it is, and try not to freak out about it. Freaking out will for sure make things worse.
What does your diet typically consist of, by the way?