Five finger breathing: a simple way to reboot your brain, calm down and be in the moment. Worry takes up your brain’s “RAM” (working memory.)

Paying attention to many senses (seeing, feeling) & body parts (hands, breath) at once crowds out worry.
The free “Breathe by Dr. Jud” app provides short, on-demand, evidence-based anti-anxiety exercises that can help you deal with stress and uncertainty. Download it for Apple devices or Android devices.