Sometimes the fear leaps upon you so suddenly, without warning, the Being is devastated before defense is possible. It comes armed with teeth with which to devour your spirit, claws with with which to rip out your soul, leaving not even tears with which to weep.
It hides, the fear, under your quiet despair, lingers under the edges of the happy times, waiting to rush through those moments of self-doubt, those cracks in the window of your ego. It is a nameless force, or else you wish not to know its name, but, in truth, inattention is a poor fortress.
There is a good verse, here, waiting to be sculpted.