For the last two years I've been experiencing the pain
I saw my doctor. He recommended Otolaryngologist who did endoscopy of my throat. Did not find anything wrong; just some redness due to GERD. Adjusting my diet, etc.
I was on Nexium; no longer taking this medication.
I also did endoscopy of my stomach; found nothing serious.
I had voice therapy that did not help.
What other tests should I do to find out what is causing these symptoms described above?
What could this be?
Have you been examined for asthma?
I am sorry to hear about your troubles. At the same time I am glad to read that nothing malignant is at play. Based on your description, I suggest you get examined for asthma, i.e. by testing your lung function before and after administration of bronchodilators or bronchoconstrictors.
Hope this helps. Please let me know if you have further questions.