Can't he just make the phone call?

My ADD husband and I have had a very rock relationship for a few years now. In the past, I've been the one to arrange for us to see therapists to try and work on our marriage. A few months ago I told him that it was now his turn to set up an appointment for us to get some counseling -- that I wasn't going to be responsible for it again. He promised me that he would, but nothing has happened. I've brought it up several times, but he has always responded that he doesn't have any time to make calls or that he is too busy with work right now. I've reiterated that if he wants our relationship to get on track that he will need to take this step. A few days ago I broke down (again) because he told me he shouldn't have to be the one to arrange the counseling -- that I didn't understand how hard it is to be him. He really snapped at me and became angry that I would even ask him about something that he had promised me to do. Not sure where to go from here. Of course I could make the call and set up the appointment myself. But what is the point of me dragging him to another round of therapy if he isn't invested enough to make a phone call? I know it's hard for him. Things are hard. But how can I make him take a significant step toward getting us on track?