Evolutionary psychology tells us anxiety is necessary for the survival of the species. This is obviously the case in social interactions as they can change our status/value in the social hierarchy which increases or decreases our chances of survival.
Like jobu said - humanity has a baseline of anxiety.
What about when our anxiety is severely deviant?
Meditation and Eckhart Tolle changed my life. Unfortunately, I still need to use medication sometimes when I get attacks.
There's so much I'd like to type out about not being the contents of our mind, Libet and free will, meditation, etc. It's only taken me 20 years to understand and I always feel like I want to tell everyone since I figured all of this out two years ago. But you can do it yourself. Buddhism, Tolle, meditation. Meditation got me to CBT. CBT brought me to Buddhism which brought me to Tolle.