Assuming you have no thyroid cysts/nodules ( ultrasound would reveal ), the sx could be globus hystericus, or indeed, your sleep apnea.
If you don't already, I would sleep on your stomach or side as when one les on their back, the tongue is relaxed and drops back to sometimes partially close the airway.
I hope your Dr. is an ENT or OTO specialist.
Various possibilities for your symptoms are overextension of the muscles,overweight,dehydration, alterations in the balance of salts in the bloodstream (such as a high or low calcium, sodium or potassium level)thyroid disorders, GERD(gastroesphageal reflux) and some neck (pharyngeal or laryngeal)pathology.
Obstructive sleep apnea can also be related to it.
X-ray neck or CT neck, blood tests and sleep studies may be needed to confirm a diagnosis.Pls consult an ENT surgeon and sleep specialist for that.
Hope it helps.Take care and pls do keep me posted on how you are doing.