I would examine the mind/body connection FIRST. What does the thyroid gland represent and what sorts of shocks or traumas can effect this gland? Certainly great food is important for healing but the first place to start is to understand what may have created this "dis-ease" in the first place.
" The throat centre and the thyroid are linked to speech and the ability to communicate. The thyroid is seen as the source of our personal power, like a little sun that shines brightly, emanating warmth and confidence. With a block there may be a tendency to be withdrawn, timid, shy and uncommunicative." (NES Health scan software)
I also recommend further exploration found here: https://learninggnm.com/SBS/documents/thyroid_parathyroids.html#Thyroid_Gland_CA
Once the conflict is resolved, adding nourishing foods (kelp, sardines, anchovies, wild caught fish, eggs and raw milk, cream and butter) will support the body during healing.