I got nothin' other than what you're already doing. If your thyroid has stopped functioning, then you need hormone replacement, and that requires bloodwork and tinkering.
Grains, legumes, dairy, possibly nightshades, and cruciferous vegetables are the five things cited as "to be avoided" (i.e., remove them from your diet completely) by the hypo crowd. Admittedly, I still eat tomatoes and peppers and broccoli, but I'm medicated and have been for a while.
Iodine. I am still utterly confused by this, but from what I gather -- avoid it.
Other than that, good luck and take care and all that good stuff.