Bravo to him for admitting (and recognizing) that he has a problem - that is always the first step to recovery. It sounds like you are staying positive, and that is the very best thing that you can possibly do right now. Just hang in there and stay strong. It will be a long road, but if he REALLY wants to, and he REALLY tries, he CAN beat this. And I have strong faith that he will
Rehab is wonderful and that is exactly where he needs to be right now, but just remember that when he comes home, it is STILL going to be difficult for him and he is going to need you then more than ever. Just try not to forget that. It takes a great while for someone to get past this, but your support is the #1 best thing you can possibly offer him.
Keep praying about it sweetie - you guys are most definitely in mine