Literally: blue – breath – spit – breath
Alternately: Trying times. Hardship and/or great anxiety. Being in such pain (psychologically rather than physically) that you feel physically exhausted and can only sigh in response.
Notes: The “blue” refers to going pale with exhaustion rather than anything we would call “blue” in the West. So the first half of the phrase refers to being rendered “pale and sighing” through your woes, while the latter half reiterates the sigh for emphasis.