For what it is worth, I tried some new VG liquid the other day (had been using PG exclusively with no problem) and had an allergic reaction on my skin. Later that evening my boyfriend noticed I was wheezing. Stopped using the juice and the wheezing went away. Tried it again about 3 days later, same thing rash, wheezing, tight chest. I do not know if those having problems have changed any aspect of their juices when these symptoms occurred, but it definitely could be a factor.
My experience with VG has been similar, however I haven't noticed a rash. Definitely feel heavy/tight in the chest with a bit of wheezing. The VG dries my mouth out completely. Even drinking water doesn't help. VG makes my mouth feel coated, similar to eating something fried. I still use it sparingly in my mixes as I love the vapor. Since much of the nicotine is absorbed through the oral mucosa, I try to remind myself that the shallow, cigar-style inhale is really all that is necessary... especially with "exotic" flavors that have lots of color. If I am feeling the need to inhale deeply, I will default to pure menthol/tobacco liquid.
~OP, I hope you feel better and you get to the bottom of whatever is causing your symptoms.
whim