Hey Pajama
Sounds like you are learning and starting to get stronger! Sounds like mostly, you just need to stick to your guns - he is off now to a facility, where he will be offered all the tools he needs to recover, if he chooses to commit to it. It is up to him now, in an environment where professionals will look after him and do their utmost professional best to get him in the right direction. The horse has been led to water.
Basically it will mean 3 months of guaranteed peace for you. If I were you, I would think of stuff to do with that time. What can you do with that chaos-free time that would make you happier? That will give you peace, contentment, strength or clarity - or just rest!
My own spouse is coming home next week. Her rehab was only 28 days. If I could travel back in time and advise past me, I would say: no matter what she does, take this time anyway. It has been good to discover what I am like without an alcoholic around.