Update on thyroid area hurting

So I posted about my Adam's apple area hurting terribly! I have concluded that I think my thyroid is enlarged. I went to the chiropractor and he did not find anything that would link it to anything regarding a fracture or bruise. I have been taking 600-800mcg of selenium for 3 days with no Iodine and pain is finally going away. I still have tightness more so after a hard work out and eating/drinking. It's not pain so much as it feels like my neck is in a vice? How should I proceed? When can I resume Iodine? I take about 100mg 4-5times a week. I was only taking 200mcg of selenium/ not sure if that's why this happened-maybe wasn't taking enough? Let me know!