a bundle of nerves
US /ə ˈbʌndl əv nɜrvz/
UK /ə ˈbʌndl əv nɜrvz/

1.
a person who is extremely nervous or anxious
:
•
Before her big presentation, she was a bundle of nerves.
•
Waiting for the exam results, he was a bundle of nerves.
a person who is extremely nervous or anxious