Are you drinking what should at first feel like an outrageous amount of water? That's not only a must for
vaping but also for digestive issues, related to vaping or not.
Another thing to try would be to stop inhaling and see if your symptoms ease up. The nicotine from e-juice is absorbed better through the mouth and nose than it is from the lungs anyway, so it could be changing your vape style would possibly help.
If the suggestions you find here don't help, it would definitely be time to head to the doctor!
Best wishes!