Changing your diet could shrink your nodules. I HIGHLY recommend you call a good nutritionist and get an appointment right away.
In the meantime, start eating tons of fresh vegetables and fruit, all organic if possible. And don't eat ANY soy. Soy is notorious for causing thyroid problems. Check food labels carefully. Every bread and packaged food seems to have soy added these days! It's no wonder so many people have thyroid problems now.
Hashimoto's Thyroiditis is probably the "H" disease you were thinking of.
OK, now go call that nutritionist. They do specific tests regular doctors don't do.
Good luck,
Honeycomb