I write about this in detail in this book:
https://keto-adapted.com/product/secrets-to-controlling-your-weight-cravings-and-moods/
I also have a supplement plan just for anxiety here (about half way down on right):
http://mariamindbodyhealth.com/supplement-plans/
Some of the main things to take are gaba, l-theanine, probiotics and magnesium.