You've been 'vaping for months' and 'all of a sudden it's rather painful to breathe'?
Odds are it has nothing to do with vaping. Humans have a tendency to see patterns where there aren't any - 'A happened, then B happened, so A must have caused B'. As a nurse, I see it all the time.
What type of pain is it (dull, throbbing, stabbing)? Where exactly? Exactly when do you feel it (inhaling, exhaling, 'end of exhale', 'middle of inhale', etc.)? Do you feel it every time you do (whatever you answered in the previous question)? Does it hurt more/less when you are in particular positions (standing, sitting, lying down, etc.) or at different times of the day (morning, after dinner, etc.)? Need more info...