Here's a special post-Valentine's Day Yo-ji for all you lovers... who failed miserably on Saturday. That's right, today's post has nothing to do with Valentine's day in general, but the only good image I could find for "blue breath" had hearts in it.
I hope that you can't use 青息吐息 in relation to your Valentine's... but just in case you can, I might as well tell you what it means.
息 is your breath, and 吐息 is a sigh. Less common is 青息, which means a 'pained sigh.' But it makes sense when you think about some of the other appearances of 青: 顔が青い、青ざめる、青あざ, 青枯れ病 (why do I know that word?), etc.
So put a bunch of pained sighs and regular sighs together, and what do you get?
1. Deep distress.
3. Involuntary exhalations caused by deep distress or desperation.
You should use this in relation to large sources of stress or anxiety, and it most commonly takes です or だ after it like, 「来週のエバリュエーションのため、彼はさすがに青息吐息だ: Next week's the evaluation, so of course he's really stressed out.」
I bought my new car with a loan, but because the payments are so immense, it's become a desperate situation.