I feel down in the dumps today.

我今天感谢到很忧郁。

Eg: I always feel down in the dumps when I go back to work after a long weekend.

每次周末过后去上班的时候，我的心情都很低落。

Oh no, you want to know that somebody else has felt that way too, and that it's OK to feel down in the dumps.

相反的，你更想知道别人是否也有这样的感觉，这样的低落情绪是否正常。