Anyway I need advice on what to do...
She wants me to either cut down or quit
This is my advice:
Cut down on - or quit - the relationship with this woman immediately. She sounds like a control freak to me.
Do not fool yourself for one second that, once you give up vaping to please her, this will be the end of it and she will let you enjoy your life in peace.
It will not be the end. It will be the beginning. Of more nagging, more badgering, more bullying. To change this, change that, give up everything that is important to you. Change, adapt, give up more and more of yourself - until there is nothing left of you. Nothing.
Run. Don't walk. Get out of this relationship while there is still time.
I was married to a control freak who showed his true nature after we got married and after we moved to his home country where I - a very young woman at the time - was in his power.
Run. Don't walk. Get away from this woman. And do not - repeat not - marry her. Unless you are interested in a living hell and then a messy divorce.
Been there. Done that. I know the signs when I see them.