I don't know what to tell you nightandday. In recovery we are taught, that our best thinking got us into this mess and that in order to move forward, we need to listen to others who have been through what we have been through and follow their advice.
As an adult child of alcoholics, your best thinking has gotten you into this relationship with this guy who may or may not be in recovery, but certainly if he's not using, he's on the verge of relapse. He doesn't live near you or with you. And he guilts you into staying with him by blaming you for a relapse that hasn't even happened yet (supposedly). If your relationship with him were a text book, I'd say you guys were a classic. :-)
However, I know that you are exactly where you need to be to be in this point in time. There is a lesson in all this and you need to learn it before you can move on.
I encourage you to learn it quickly. :-) Because you sound like such a nice person with so much to offer in relationship. It just doesn't seem like this man will ever really be able to walk along side of you into a beautiful relationship where each of you holds equal status. Certainly not in the present time. Certainly not with the skills he has. And you can't change him or make him better.
He's sick honey. Mentally ill with self-induced problems. Addiction. Not cancer. You can't fix him. No doctor can fix him. He has to do it on his own. It's hard work. He has to want it really bad. And as long as he's wallowing in self-pity, he doesn't want it really bad. He has to be greatful and be willing to do whatever it takes to get better, without complaint. From your description, it just doesn't sound like he's there yet.
You can fix you. If you work at it and listen to the experience of others who have been through what you are going through... and follow the advice your therapist. That's what you pay him/her for. Right?