Key points in a relationship... Be witty, keep it refreshing, if it isn't, it won't last. Make sure she is comfortable with you getting high all the time man. If she isn't, get a new girlfriend or stop smoking so much. The Pendulum swings both ways. Like she said, before getting all upset, spend some money on her. Dates are key, not even dinner, anywhere. If your broke, take a walk, it helps. Smoking the 'dankest weed' ever isn't worth being lonely. Fortunately, somebody came up with the good idea of eye drops, so, even if you are stoned or a little buzzed, you can play it off as tired or maybe like myself, you are a lot happier and easy going.
Don't be desperate and run after her in a mall. Girls like a chase but not literally, and maybe it was temporary, just get your act together and if the pieces fall back into place, hooray; if not, there are a lot of different women on this earth to suite your personality. Pick up a hobby, like growing things or building a car. Like everyone else said, re-unite with your friends. Hopefully you didn't blow them all off for this girl but she even too, has a good point.
Last thing, don't get into an argument with her over this post. It will only make things worse. I don't know if I fully recommend change of a person because who you are is more important but try to be more 50/50 with women. They are inevitably, your other half. Marijuana is there to take the edge off. Anything in excess is unhealthy.
Good song: Baz Luhrmann - The Sunscreen Song
It applies to everyone.