Suggest Treatment For Hashimoto S Thyroiditis

Hi, I am 57 yr old male and I have hashimotos thyroiditis, and am under my endocrinologists constant care (every six months) with blood work and checkup and take 150mcg synthroid and not diabetic. Today within 5 minutes while sitting down without physical activity my throat became very sore and harder to swallow than ever in my lifetime. No cough at all. I also felt pain up into my temples and felt dull pain like my ears just popped when they didn t. I have no problem breathing or have any other pain. After 20 minutes I can swallow a little easier but it still is sore to. I was not eating anything when it came on, but had been chewing sugarless gum, and had 1/2 can of diet coke which I drink maybe three cans a week at most. Please advise, Thank you.