go off the deep end

US /ɡoʊ ɔf ðə diːp ɛnd/
UK /ɡoʊ ɔf ðə diːp ɛnd/
"go off the deep end" picture
1.

大发雷霆, 情绪失控, 发疯

to become very angry or emotional, or to start behaving in a crazy way

:
When he heard the news, he really went off the deep end.
当他听到这个消息时,他真的大发雷霆
She tends to go off the deep end when she's stressed.
她压力大的时候容易情绪失控