be nervous of (one's) (own) shadow

be nervous of (one's) (own) shadow

To be easily or constantly spooked, nervous, timid, afraid, or fearfully suspicious. I can't say I have much faith in Johnny helping us on this expedition—that boy's nervous of his own shadow!
See also: nervous, of, shadow

be frightened/nervous/scared of your own ˈshadow

be very easily frightened; be very nervous: Since the attack he’s been a changed man. He’s nervous of his own shadow and doesn’t like to go out alone at night.