It sounds like a typical case of 1st stage (hyperthyroid) postpartum thyroiditis.
You'll need to have this monitored closely by repeat labs (insist!), consume goitrogenic foods while you're hyperthyroid, like raw broccoli,raw cabbage and raw peanuts. which can lower thyroid function a bit, but not when they are cooked/roasted.
Also by consuming raw natural sea salt and avoiding nori
and seafood, you will also have less dietary iodine, the base
substance for thyroid function, but this will take a few weeks to work itself into your body.
I hope this helps.
Best wishes,
Niko