The usual suspect is dehydration. It is unbelievable how much water it takes from your body to vape. That's the one big downside of
vaping. If you don't get it by drinking your body has to rob it from your blood, tissue, etc. It can be very serious.
Second guess is a PG or VG reaction.
Third guess is that you are allergic to the filler in the cartomizers.
Fourth guess is that you're allergic to the flavors
Happy to send you 3ml samples of pure pg and pure vg sample at your nic level with no flavor. Try each one and see how that works. PM me if interested. If that seems weird, I understand. However, you need samples of your nic level juice in a PG base 100% and a VG base 100%. Vape it in a clean atomizer rather than through cartomizer filler. Add each thing a step at a time. over several days. You'll figure it out. I'm so sorry you have to smoke again. I hope you're back to
vaping soon.