have the blues

have the blues (third-person singular simple present has the blues, present participle having the blues, simple past and past participle had the blues)

1. (idiomatic, informal) To be depressed; to have low morale; to feel sad.

   I've had the blues ever since my sweetheart left.

• “have the blues”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.