I would go with conventional medicine, but I decided to keep an open mind and look up Ayurvedic treatment for the thyroid.
Gugul is a supplement recommended.
One of the best known Ayurvedic herbs in India is gugul, the A resin (organic substances that exude from trees and plants) from the Commiphora mukul tree, widely used in Indian Ayurvedic medicine, which is now becoming more popular with practitioners of Western alternative medicine.
Ayurvedic practitioners also used gugul for weight-loss. It was thought then that the herb acted as a metabolic tonic, but its mechanism of action was unknown. It is now known through research that gugul has an effect on the thyroid gland. In short, gugul raised the levels of circulating thyroid hormones, which may account for its ability to regulate obesity and cholesterol levels. In summary, gugul offers an interesting potential and it is time that we reexamined this wonder of the past.
If this is the path you want to choose, I would still consult with a doctor, and have your conditioned checked monthly with blood tests to see if there is progress and to keep you out of harm.