Sticky phlegm-like fluid forms in my mouth?

Sticky phlegm-like fluid forms in my mouth whenever I drink or eat something sweet. This has been happening for as long as I can remember. I always have had the feeling that I have phlegm building in my throat for years but recently this sensation developed into the feeling that I have a lump in my throat not necessarily phlegm but rather something is inflamed but nothing hurts though; it just bothers me sometimes. The feeling is more dominant in the right side of my throat just below my Adam's apple. I feel that I have hypothyroidism but doctor's won't diagnose me with it since my TSH, FT3, FT4 are in the "normal range"; FTs are low normal and TSH in high normal. Also, when I drink Yakult (a milk-product), it curds in mouth leaving white gelatinous semi-solid curds. Are any of you familiar with this condition?