Also, you should look at what kinds of foods you are eating. There are foods that are 'goitrogenic' that impair your thyroids ability to function. Among other things you should limit/or avoid walnuts, soy products, raw brocolli/cabbages, peaches, peanuts, strawberries, etc. If you Google 'thyroid avoid foods' or something like that you'll get a more complete list. Because your thyroid is sort of the command centre for lots of functions in your body, you gotta take care of it so knowing about these foods is important. Also, you might not be getting enough iodine in your diet if you are using a plain sea salt, switch to an iodized salt.
And while it is a bit of a pain in the backside, you don't need to be scared. Just take the little pill which simply puts more of the thyroid hormones into your body, watch what you eat and life should go on the same. The hardest thing that I had to deal with was a 'peanut addiction' which I knew was a no-no but I finally got that under control (I don't buy them anymore). I read that 8 out 10 women in North America have thyroid issues, most of which are undiagnosed. Apparently it is some sort of auto-immune disease. Who knows, maybe the prevalance of those kind of issues (auto-immune diseases are varied and numerous) has something to do with the abuse that we've heaped on our environment, from 'bad' foods (think genetically modified, to stuff dosed with Roundup, to impure water and air and whatever else we've done to it, as well as modern day stressors, etc.)