A feeling of constant unfocused anxiety was one of the first symptoms of long covid that I experienced after my (mild) acute infection last June. It helped to realize that it was, in fact, a symptom of long covid. For the most part, I've learned to ignore most of those bodily signals, especially when they're not connected to any actual "threat" (I realize this is not something everyone can do). However, this strategy is limited when faced with real things that I'm anxious about (e.g. a long plane trip for a family event...not because of fear of flying, but because I feared doing something stupid because of covid brain fog).