Anxiety is like dangling off of a cliff and desperately holding onto a branch for dear life... when the ground is only 6 inches below you. We are all exhausted from trying to hang on. We stay constantly tense, vigilant and scared waiting for the BAD THING to happen, the seizure, the heart attack, etc. and all of this "hanging on" takes its toll on our mind and body creating more symptoms, and causing us to hold even harder. But the truth is if you let go of all of the fears and worries (the branch), you're not going to have that heart attack or seizure or fainting spell. You're just going to land on the ground 6 inches down. And your body and brain will be relieved that they don't have to spend all of their energy hanging on anymore.
Something a therapist explained to me once. I thought it was a great metaphor.