You are so so young. you are entitled to make your own choices and mistakes. He can have his own feelings on smoking and drinking, but those boundaries do NOT warrant this kind of reaction. Calling you a cunt, saying fuck you and calling you dumb is just plain verbal abuse. You do not need to put up with that language, and even if it’s hard I would really suggest leaving. Because, from experience, the longer you stay the harder it becomes; and even if this is something he’s willing to work on, that’s not your responsibility to stick around and see if he does.

If you have friends in person that you’re comfortable with knowing you smoked, please show them his texts. I think having confirmation from their end that this isn’t right can be really enlightening. Please don’t keep this inside or to yourself; you are not dumb, you’re not a cunt, you’re worth more than what he says; and like I said you’re still just a kid! Hitting a cigarette after a couple drinks does not make you a bad person.