I have used books by Marcus Aurelius and Epictetus a lot. Many of their meditations are available on the Internet. the Cognitive Behavior Therapy developed by Aaron Beck and Albert Ellis are based in great part on the works of the ancient Stoics.

There is a wonderful book called "The Worry Cure" or "The Worry Remedy" by a famous Cognitive Therapist. I gave my copy away but I think the author's name is Leahy. I might be wrong. Reading it was a real life-changer for me. It was just brimming with wonderful insights and meditations. Wish I still had that book.

Thank you so much for your post. I sure hope the person you mentioned is able to get better. Anxiety can be so cruel and brutal.