blue funk, in a

In a state of panic or terror. For example, Just because the bride’s mother is late, you needn’t get in a blue funk. This term originated in the mid-1700s as in a funk, the adjective blue, meaning “affected with fear or anxiety,” being added a century later.

In a state of dejection, sad. For example, Anne has been in a blue funk since her dog died. This usage employs blue in the sense of “sad”—a meaning that first emerged in the late 1300s. Also see have the blues.