A no brainer to see your Doc. IMO. You can also reveal to him that you've stopped smoking. Most of our Dr's have been very supportive of vaping. Could also be, as others have reported, you have a sensitivity to PG. Myself I am sensitive to Ethyl Maltol aka Cotton Candy. Also one other point that no one has touched upon. vaping is dehydrating and if you're drinking coffee (more than 4 cups= dehydration) or caffeine laced soft drinks the dehydration becomes severe. I cut my java down to 3 1/2 cups per day from 10+ and no longer drink Coca Cola. I drink 1 1/2 litres water per day.
Good Luck.
That's a GREAT point. I concur.