i think its about she taking drugs and wait for the buildup" is to wait for the drug to make her high, and "and when we come down, we do it again" that she take more drug when the last drug effect looses. "again and again" taking drugs again and again then she try to stop, so she tells the drug that "we should not be friends". and "if you stay around" she will use the drugs more than if they not was around (if they was friends).
i think its about she taking drugs and wait for the buildup" is to wait for the drug to make her high, and "and when we come down, we do it again" that she take more drug when the last drug effect looses. "again and again" taking drugs again and again then she try to stop, so she tells the drug that "we should not be friends". and "if you stay around" she will use the drugs more than if they not was around (if they was friends).