What do i do if my girl wants me to stop smoking and drinking and she wants to keep doin it Confused?

She is the greatest person to me but i want to stop only when she stops she has been drinkin and i have been smokin behind each others backs (she doesn't know only i do) we are tryin to have an honest trusting relationship. But we can't stay on track. Please everyone i need advice. Breakin up is a last resort