Sometimes the anxiety just has no rhyme or reason...:/
It may have been something as some as your shower being too hot...which made you a bit woozy, that then started anxious thoughts about
your physical symptom...creating more anxiety and symptoms in a vicious cycle. This has happened to me before.
Be sure and keep up with your anxiety management regimen. Practicing your coping and or therapy skills is key!
Keep posting as well so we can keep you in support.