What Causes Enlarged Thyroid And Intermittent Sore Throat?

I had an ultrasound that said my thyroid was slightly enlarged and I recently stopped eating meat 3 months ago now I have sore throat that is on and off. I ve had a sore throat on and off for a week. My Dr said I m allergic to smoke. It hurts when I smoke and after.Today I stood by a woman today that was smoking and my throat hurt again and my throat started cracking when I spoke. I have not eaten meat in three months is this normal for vegetarians to have allergies to smoke. or is this due to lack of iron? Please help