Whether it's Hashimoto's or any chronic condition, it's been determined that inflammation and the chronic fright or flight state are the reason behind almost all of them. Dysautonomia is not new; I learned about it over a decade ago and knew it made sense but was difficult to treat. Healing the brain is difficult as we have found out watching The Broken Brain series.
We've discussed stimulating the vagus nerve by throat exercises since the nerve runx behind both ears and the palate. There may be something more we can do. This explains what goes wrong.