From what I've read and been told by those evil pain inducing people in the dentists office... smoking and nicotine causes your veins to constrict.
vaping appears to deliver less nicotine or at least the size of the nicotine molecules are larger and not absorbed as efficiently as from smoking tobacco.
Could be you are experiencing increased blood flow in your mouth and dental areas as a result of quitting smoking and that has riled up the nerves in your teeth... It's a possible side effect of quitting. Give it some time and if it doesn't go away... maybe a trip to the dentist is in order.
I hate suggesting that to anyone other than people I hate... Dentists and especially oral hygienists are just evil and enjoy inflicting pain on others. If I hear the words... your gums bleed easily... why do I have to point out that when sharp pointy objects are stuck into my tissue anywhere on my body... I'm gonna bleed!!! Those people paid thousands of dollars for medical school and not a one of them learned that simple fact!!! Sorry about the tangent... did I mention I hate dentists..?
x2.
My advice would be to drink more water and to use a sensitive toothpaste (Sensadine, generics work well too) until you can see your dentist. Your gums are healing themselves from many years of smoking and are bound to have some areas that aren't being protected.