Get well soon, Victoria! That is very good advice you received, Victoria. We were discussing this issue on another forum recently, and although we were discussing the enjoyment of Japanese green tea, we all seemed to notice a major decrease in colds/sinus infections. And those who had colds, they were not severe and seemed to get over them very quickly.
For me right now, I am just now getting to my first tea, Japanese green, SURPRISE!!! Takumi sencha from Yame prefecture. This is grown like sencha in full sun, but the varieral used is Gokoh, the same varietal used for gykuro. Someone coined the phrase/nickname for this tea here, "Gokoh (gyokuro) grown in the Sun."