Was there ever any thought that your mouth and lip issue was not GERD related? If your doctors were confident that you would be helped by the surgery, then just realize that the recovery takes time. You've had the surgery, and now it's just a waiting game.
When my asthma doc wanted my wrap checked he sent me first to an ENT to scope my vocal chords, then to a surgeon for the complete battery of tests. This was at 2 years post-op. I don't think they'll do much more than a barium swallow or maybe at most a 24hr PH monitor, but honestly, I'd be surprised if they didn't just tell you to give the healing more time.
It gets better,
“Always say “yes” to the present moment. What could be more futile, more insane, than to create inner resistance to what already is? what could be more insane than to oppose life itself, which is now and always now? Surrender to what is. Say “yes” to life — and see how life suddenly starts working for you rather than against you.”
― Eckhart Tolle