Hi CaughtInChaos, so sorry to hear your troubles. It sounds as though youre on your last nerve and who can blame you?
From your description it seems like your partner (and/or his addiction) has been carefully manipulating situations and by implication you until he has things exactly how he wants them. His masquerading by choosing another drug and clear manipulation of your counselling sessions are obvious red flags. If you think about it, shifting his addiction and using your counsellor to pretend he's doing all that needs to be done allows him to carry on regardless. If he has no intention of changing then the situation you describe is tailor made for both him and his addiction. Why would he change when he has it so good? There is nothing about that situation that even hints that he is serious about respecting you or your relationship. And it is so painfully obvious what he is doing. If he thinks he is fooling anyone he couldnt make it more obvious if he wrote it in letters ten feet tall. There are many on here who can offer much better advice than I about navigating this kind of abuse (as Hechose drugs says, it's nothing short of abuse). Maybe you should start considering your boundaries and decide what youre not prepared to put up with.