This is a classic case of Hashimoto's Thyroiditis. The excessive salivation is not typical, but could be part of too much thyroid hormone and the low TSH clearly indicates too much - so 50mcg seems like a reasonable dose.
Although the GI tests were fine, you symptoms are suggestive of reflux disease. The thyroid could cause this and more time with appropriate TSH levels (in the low normal reference range) may help shrink it down and may diminish this sensation.
Regarding the antibodies, selenium 200mcg/day is shown to help a bit.
Ultrasound -- done by the physician -- is the best way to follow the size of the thyroid and the possible nodules seen.
Rest of my long post, sorry...
A year ago I went to the Internist with a feeling of something stuck in my throat and went through a series of GI tests that turned out perfectly normal.
I still have the ever-present sensation, but it's a little more pronounced now, especially if I am flat on my back, so I sleep propped up on pillows. My throat, on the right side, sometimes pulsates/spasms and I have simultaneously had facial spasms (lower jaw) as well.
I realize the "itis' in thyroiditis means inflammation, so I suppose this is normal?
Could the thyroid have grown much more since April?
Should I have follow-up imaging studies? What type?
Thank you for your response, it is much appreciated.