do I have hypothyroidism?

A while back I went to a doctor when I was having problems with tonsilitis about having my tonsils taken out. He felt around on my neck and told me he thought I had an enlarged thyroid. He made me drink some water and watched my throat, and he was convinced I needed to see a doctor over it.

I never went, because I don't have insurance. Then, back in January, I started having bad problems with my knees aching, but only when sitting. I went to the doctor for that and he could not find any problems. The pain has persisted, and if I do too much physical activity, I've even noticed that my calves will swell. Then, I gained 30 pounds in two months for no reason. I've been exercising for two months three times a week to no avail. I sleep eight hours a night, and yet, I have found I will take three to four hour naps in the afternoons, and can still sleep at night just fine. My voice is hoarse and breaks a lot, but I always blamed that on smoking. What do you guys think? Does this sound like hypothyroidism?