go to pieces
US /ɡoʊ tə ˈpiːsɪz/
UK /ɡoʊ tə ˈpiːsɪz/

1.
andare in pezzi, crollare
to become so upset or nervous that you cannot function normally
:
•
After the accident, she completely went to pieces.
Dopo l'incidente, è completamente andata in pezzi.
•
He tends to go to pieces under pressure.
Tende ad andare in pezzi sotto pressione.