I spent years in traditional therapy trying to get relief for my anxiety disorder but nothing was really helping. Fortunately a friend referred me to a Somatic Experiencing Therapist and my life completely changed. Within a few session my panic and anxiety decreased by nearly half, after a year it was gone. This therapist understood the body/mind connection through the vagus nerve.
This article clearly explains the vagus nerve and gives 8 ways to stimulate it, I would add one more... GOOD GUT BACTERIA! Earlier I posted the Radialab episode explaining the relationship between good gut bacteria and the vagus nerve, you can listen to it here. The segment begins around minute 17.