Hi Ashley --
Believe me, I know how frustrating this is. I don't know enough about your symptoms to comment, other than the fact that I'm keying in on the fact that you say you have a "perfectly normal stomach," instead of a "perfectly normal throat," for example. Do I remember reading that you were diagnosed with a gall stone? Can't remember. Please mention all this to your doctor.
I can tell you my experience with my last pH test, which was an impedence test. I had to travel 350 miles one-way to have the test administered, and had to stay overnight in a hotel. There was a lot of stress built around this single test, and I had a lot of discomfort with it. I was constantly fighting the wire where it makes the turn from my throat into my esophagus, probably doing a lot of unconscious squeezing with my throat, and lots of swallowing. Anyway, after all this trouble and expense, the results of the test showed no reflux episodes into my throat, when I know full well that I do. So, the long and short of this is I understand exactly where you're at, and my stress most likely prevented an accurate test result. (It still showed the expected amount of reflux into my esophagus.)
The reason I'm sharing this is that it might be the stress you're experiencing that's shutting down the reflux through muscular tension -- not to make you more stressed out! Relax, relax, relax.
I'm sending good thoughts your way, that you will receive the perfect attention and treatment you expect, and that your doctors will discover and diagnose what they need for you to find lasting comfort. Relax, and know that you can not be left in limbo...