IDIOMS

down in the dumps

(idiomatic) Sad; lacking engagement or enthusiasm.

Example: 1886, Edward Payson Roe, He Fell In Love With His Wife, ch. 2:
  "You've got down in the dumps and can't see what's sensible and to your own advantage."
2009, Brian McVicar, "Some in Mich. turn to ice fishing as economy dives," chicagotribune.com, 2 Feb. (retrieved 3 Feb 2009):
  "Being out of work sometimes makes you feel down in the dumps and being out here with my buddies helps."