go into a tailspin

Lose emotional control, collapse, panic. For example, If she fails the bar exam again, she's sure to go into a tailspin. This expression alludes to the downward movement of an airplane out of control, in which the tail describes a spiral. [Early 1900s]

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.