(one's) nerves are shot phrase
Used when one suffers from mental or emotional exhaustion
His nerves were shot for weeks after his mom's death.
Ever since losing his home in the flood, his nerves have been shot.
She was taken to the hospital because her nerves were shot.
To be very anxious
Said when you are too tired to do something
To feel that unpleasant or dangerous things likely happen to you
Completely fatigued.
The origin of this phrase is not clear.