to be upset; to lose one's composure; to lose self-control; to go to pieces; to be shaken up; to break down; to be flustered; to blow one's cool
to put in disorder; to mess up; to disturb; to scatter about
突然の訃報を聞いて取り乱した。
She fell apart when she heard the sudden news of the death.
どんな状況でも取り乱さずにいなさい。
Keep calm no matter what the situation.
泣いてばかりで取り乱している場合ではない。
This is no time to fall apart and just cry.