Yes I would see a doctor at this point to discuss options. It's possible that
vaping isn't for you but there are other harm reduction products, like snus. Since you have asthma, it's possible that may be safer for you. If your doc gives you the go ahead however, you might try
vaping unflavored mixes of VG/PG percentages without flavorings to see if it's the flavoring (it could well be). If you find a mix of unflavored that works, you could then try adding in flavors.
See your doctor and see what he/she thinks. Vaping will be here. Until I got really bad pneumonias and whatnot, I've had mild childhood asthma and smoking didn't really aggravate it at all, I *sometimes* think it improved it a bit. But not by the end, not even close. The amount of money I spent on nebulizers, inhalers, and other medical treatments during my pneumonias was OBSCENE.
I really hope you can get things working, but given what is happening when you vape, I'd consult a doctor first.
Best of luck,
Anna