My boyfriend is addicted to shooting up cocaine. He does it as far as I know, every weekend, but probably more than that. He tries to hide it from me but I keep catching him. I tell him that if he does it again, we are over. Then he does it and he begs me to stay and says that I'm the only hope he has to ever stop. When I caught him last night in the bathroom, I told him to choose doing it or me, he said that he was gonna do it and he did. I feel bad to give up on him, we have been best friends for eleven years, dating for almost a year. We were planning to move into together. I feel like if I keep staying, he will keep doing it, but I feel like if I leave, I'm just deserting him. I will be open to any advice.