I'm not sure exactly what it is you are being tested for?

I will say thyroid cancer isn't anything like leukaemia or pancreatic or lung cancer. The more common ones come close to 100% survival rate among younger people (younger being under about 50) and even among older people the rate is only slightly lower. (Let's put it this way, when I was diagnosed, I went reading everything about it I could find and came across some studies on various things that discussed how whatever factor affected reccurance rates, then added something along the lines of "we also meant to study whether it affected survival, but we were unable to find enough people who died of thyroid cancer to get accurate stats!")

It also doesn't require chemotherapy or radiotherapy, except in rare cases, so you aren't undergoing treatment for months. They generally just remove your thyroid and you might need radioiodine treatment, but that again is a one-off and has no real side affects (I got a nose bleed about two weeks after it; that was the extent of the effect it had on me, one nosebleed).

It sounds like you have concerns about some other form of cancer too, but just wanted to reassure you on that one, because after the experiences you have had, you might be expecting far worse to be the result of thyroid cancer.

I will add that a lot of people have thyroid nodules and very few turn out to be cancerous.