I do not believe that your confession was valid as you must have a contrite (truly sorry) heart to the fullest extent that you can. You must also have the intention to not commit the sin again.
Smoking marijuana is a sin, just accept it. I feel sorry for you. I really do. I’ll be praying for you. Smoking marijuana is illegal and drinking is not, partially due to the fact that marijuana use (even in moderation) is worse than drinking (in moderation). It’s illegal for a reason. Our country was founded under God, as we are “One nation under God”. The laws that the government has established are just loose versions of the laws of God. Therefore, if it’s illegal (against the government), it’s most likely against God as well.
I can barely understand why even a little drink isn’t considered harmful by people. It is a fact that alcohol consumption, however little, immediately impairs one’s judgment by depriving one’s brain of oxygen. It is also a fact that today’s alcohol is far more potent than that in Jesus’ day.
Either way, God loves us very much, and we must allow Him to love us. This means that we mustn’t allow other things to take His place. One cannot pit oneself against God. You’re too small to box with God, as Father John Corapi once said.
I really feel sorry for you. It’s a psychological fact that when people, deep in their consciences, know that something is wrong with what they’re doing, they try with all they can to either hide it or justify it. I, myself, have been addicted to a few sinful habits that I’m still trying to deal with; particularly those associated with lust. I used to be in a hopeless, despairing spiral thinking that I was never gonna get out, and I was even trying to deny that there was anything wrong with it at times. Believe me, you should just admit that you’ve got a problem, as it’s the first step to healing. I’m gonna be praying that you come to rid yourself of your habit and repent.