go into a tailspin

[go into a tailspin] or [go into a nose dive] {v. phr.}, {informal}To fall or go down badly; collapse; give up trying.

The team wentinto a tailspin after their captain was hurt, and they were badlybeaten.

2. {informal} To become very anxious, confused, or mentallysick; give up hope.

The man went into a tailspin after his wifedied and he never got over it.