Sounds like you have a serious thyroid problem. Get that checked out first. At the very least, get a blood test (CBC with TSH and T4). Possibly see an endocrinologist.
Yes, the lump could be Hodgkin's, but it also could be an ordinary infection, too, or lots of other things. (Lymph nodes are supposed to swell when you are sick--that's your body figuring out what kind of infection you have.)