I have to believe there is something else going on here as well. I’m a parent and have to say that vaping is pretty gross but not an excuse to cut your kid off. I have a hunch that they are not entirely happy with your college situation and have taken your vaping as an excuse to pull out.
I think you should simply sit down with them and have an adult discussion about the vaping, the costs of college, and what you are going to do differently to warrant the investment in your future.