A: You may want to look into supplementing with B12. This may help a lot of random symptoms. I recommend sublingual or injections for B12, as many people don't absorb it properly. As long as you're not a vegan/vegetarian, betaine with pepsin will also help you get the B12 from your animal-based foods. Some of the common reasons for B12 deficiency are low stomach acid, vegan/vegetarian diets, SIBO, H. pylori and other gut infections. I recommend testing for H. pylori, SIBO, as well as antibodies for pernicious anemia (parietal cell antibodies) as a starting point, as these are all very common in Hashimoto's and can be important root causes. Here are some articles to get you started:
How B12 Deficiency Affects Hashimoto’s
Hashimoto’s and Graves’ Remission after Helicobacter Pylori Eradication
Could SIBO Be Preventing Your Remission from Hashimoto’s?