All those go hand in hand when you go through prolonged stress. The stess is using up your adrenaline, putting stress on your thyroid and causing inflammation in your gut and brain. Then it uses your happy amino acids up.
Easiest cheapest thing to start with is to train yourself not to stress out. Yes it's hard but that is part of working your way out of this. Replenish your happy amino acids and start eating a more anti inflammatory diet.
Raw coconut oil and coconut water can give your thyroid a boost and bring it back in line. Start slow with a Tablespoon a day and note your reactions. Taking your temp using basal temp in the morning is a good way to gauge the thyroid. It tooks about two months to the day for my thyroid to kick in. You can also get your thyroid going with alot of different essential oils. They work well for alot of people but for me they got my cortisol going too much but hen I tend to be hyperadrenal.
Look into amino acids that help boost your mood and help you relax. "The Mood Cure," is a book that has excellent information on that.