Thyroid Enlargment

For a couple weeks now i have had a enlarged thyroid which has been very fustrating becuase i can hardly eat i lost over 25 pounds which is good but not good because its uncomfortable to swallow and eat food. i go get a nuclear test tommorw i am kinda scared a little i would like to know if someone  knows anything about a enlarged thyroid and does is shrink and how long does it take? i really would like to sit down and eat thaksgiving dinner with my family. Its been 3 weeks since i can actually sit down and eat like a normal person and really bad symptons also and bad moods. it is not a good feeling at all.. what can i do?