I have already encountered this phenomenon; there is a flavor that simply irritates, makes me cough, suffocates me, just as you describe. I probably can’t tolerate one of its components or flavor carrier substance.
You can try aerating it; it helps with melon flavor, the acetone smell decreases (although after a while it also decreases without aeration if the flavor is good quality), but I don’t think this will help with this one either, because the problem isn’t the disturbing smell, but that it irritates.
I found among the reviews that it made others cough too.
I had a similar experience back then with the ‘pistachio ice cream (cantaloupe, mandarin)’ flavor, the result: it ended up down the drain.
Just like you described, it chokes, the vapor is watery, and sometimes I coughed from it too.
I don’t think it went bad instantly, as @Zsee wrote, there is irritation from one of the components. Venting it didn’t help either.
Last time, I had a creation that smelled like acetone super glue as an aroma. After mixing, a month later it “only” smelled like super glue. And the taste… it also went down the drain
I’ll definitely try it! I still have 115ml of it, so there will be something to experiment with. @Zsee I’ll give it another chance, maybe we’ll find common ground somewhere.
Correct, I would still try with it (e.g., changing mixing ratios, ventilation, mixing with other flavors, perhaps even vacuuming with a syringe, etc.)
Under current conditions, one shouldn’t waste or be picky
it also went down the drain 
