Sounds like we're all trying to experiment and not achieving success.
I'm sorry this happened to you. Which I2 did you take?
I would agree with the goitrogens for a little while. Take lots of C and selenium. Maybe eat some cabbage and kale for a while? Broccoli too? Broccoli will get you goitrogens and selenium in one punch.
If it were radioactive I believe the KI would actually be helping you because KI will displace the radioactive and reduce damage.