I don't know if there is much of anything that you can do if he is unwilling to put in any effort (which is what it sounds like to me, please stop me if I'm wrong). I think change is possible, but both parties must be willing to try. I can understand why your therapist let you both go as clients. I think the best thing you could do right now is to get yourself into individual counseling in order to work on your codependency. You can get tips to help your codependency online, but I honestly think that a therapist would help you the most.