gf wants us to go sober

Reading through this and the responses, if you relapse well then shit. However, do you plan to stay on drugs forever?
Once you build a tolerance to the chemical in full you're gonna aim to hit something harder, well done on becoming a junkie.
Your other half has the right idea, get clean or get out. She doesn't want to spend her life with a waste of space.
FYI: That fact you're having to question if you should drop drugs for your girlfriend and a better relationship says a lot.