Hey there!
Remember that this is his recovery. And, like NA says, "just for today" he is clean and sober. And that is wonderful. He's taking it one day at a time. No one can guarantee that he won't mess up again two year from now, but no one can guarantee that he won't mess up tomorrow either. Believe me, if an addict really wants their doc, they WILL get it, no matter what you take away.
My point is that HE has got to be able to take credit for HIS recovery.
A year and a half is a ways away. A lot can happen in 18 months. So, wouldn't it be easier to let him worry about whether or not he can be clean on his own, and in the mean time, focus on you??? That way, no matter what mistake he makes, or doesn't make, your own healing can take place. You cannot heal yourself and him too; he's working on him, so you would be helping him more than you realize by helping yourself.
I hope that doesn't sound more harsh than I mean it. It's just that my mom does the same thing with my sister... and my mom is constantly a nervous wreck. She doesn't deserve that, and neither do you.