Increase inhibitive signalling and decrease excitatory signalling. I used to be mega anxious all the time until i went hard in to push my physiology the other way through food and natural (vitamins etc, not herbs) supplements. Of course i pushed way too hard and became horribly depressed and fatigued for a year or two, but I'm never truly anxious any more. Liver, magnesium, zinc, vitamin c, b vitamins, being adequately fed, avoiding caffeine/tannins, vitamin D, eggs, meat, glycine, theanine, can all have an anxiolytic effect. And if you managed to get depressed and tired like me, it's at least an opportunity to socialize without a psychological failstate since you'll be too zonked out to get anxious, and then when you feel better you have experience with the stressful situation which decreases the intimidation factor.