Trapper/kcmo nailed it, you 've experienced what many others experienced when first dislodging stored toxins, from somewhere in the brain, maybe the pineal.
Typically one experiences that the first few times. I know I did, years ago and it alarmed me equally but turned out to be no big deal. That's in my case only, and cases of others I've read about, which you shouldn't take as a guarantee that you'll have the same since we're all different and its impossible to diagnose anyone over the internet, regardless of whatever Johnny-come-lately know-it-all types may show up from time to time. Thats why my default position is to always recommend Iodine supplementation be done under MD supervision, with a loading test being done, even though CZ has disclaimers.
Many others have expressed increased mental clarity afterwards of eliminating toxins accumulated, via Iodine supplementation. I could write a book on this but the pay isn't enough, and I put enough hours in educating anonymous people who never gave anything back - no big deal but I reached my limit of free giving long ago. There are others knowledgeable and with kind hearts who are willing to contribute - just keep asking questions and folks will probably answer. Or sift through the old forum pages and find it - its all there. Befriend W and T, they've been at this thing since over 10 million page views ago and know it inside out from the onset, and they know more about Iodine than 90% of the MDs licensed in the various several states of the Union - a very sad, but true situation.