I Have Graves Disease And Had The Iodine Treatment A

I have graves disease and had the iodine treatment a year and a half ago. A few months ago my numbers dropped drastically causing me to become very sick and needing a supplement. I've been taking my meds regularly and not missing a single dose. I take 88mg of synthroid every morning. The last week I've had a constant migraine right on my temples. Could my thyroid be back to over active and causing this or could it be something different all together.