You sure lead an exciting life, Nemo!
There are black hornets (or maybe they're paper wasps) ALL over the place in New Hampshire. Every spring, I have to go around the house and dispose of the nests. I usually find seven or eight, some waaaaaay off the ground so I can't even spray 'em before knocking them off.
It will be better when I live there. I can get the nests while they're still small.
Sorry to hear about the stings. I thought my son had the record with six stings the time at boy scout camp when he sat on a log they'd moved into. You just broke his record!
Does the baking soda help? I hadn't heard of using that before, but now I have. The article I see also suggests "colloidal oatmeal" or hydrocortisone cream.
If you get nauseous, get yourself to a doctor. It suggests an allergic reaction. If you aren't allergic, the pain should decrease in a few hours.