My PG allergy developed over about a year and a half, progressing as time went, eventually I had to start making my own
ejuice. Forget about flavor for now, order yourself 1 liter of Vegetable Glycerin and 60ml of Vegetable Glycerin based 100mg Nicotine, remove 60ml from the Glycerin bottle and pour in the nicotine, shake this thing like hell, over and over and over, try to vape it for about a week and after 3-4 days your symptoms should start subsiding.
I later determined my acceptable levels of PG for me it's about 9-10% PG where I don't have any symptoms show up a lot of store bought
juice even though it is max vg flavoring is generally PG based and there is up up to 25% flavoring in some flavors.
Edit* looks like a nickel allergy then, my friend has this, he's a lead guitar player, a quite amazing one the problem is he can't get the sound he wants from stainless steel strings :/ He gets all sorts of problems on his hands from this.