You should be made aware that there is more than one type of thyroid cancer. The very worst kind and hardest to treat is very very rare. There was a supreme court justice who passed away a while back with that type.
My paternal aunt had to have surgery and it turned out that she was two different forms of thyroid cancer. Her mother, (my grandmother) died from thyroid cancer, but that was back in the 50's and she didn't go have it seen about until it was to late. My aunt is doing beautifully now and we have no reason to think that anything else will happen to her along these lines.
Thyroid problems, diabetes, are both auto immune related.
It is rather amazing actually how many conditions are auto immune related. If doctors could just figure out how our immune system really works, they could cure just about anything...
You will be in my prayers for a speedy recovery!