s Thyroiditis or
Graves Disease. Neither of these diseases are curable, but the resulting hyper or hypo are treatable. Many/most of us on this forum have one or the other, very few have both.
As noted, nodules are very common and are, typically, nothing to worry about. I, personally, have several of them.
Even in the unlikely event that you would have cancer, thyroid cancer is the easiest of all to cure, by removing the thyroid and taking the cancer with it.