Beachy - I am truly sorry that you are going through this and you've got a lot of wonderful input already.
I'm a recovering addict/alcoholic and have been struggling with addiction for 11 years now...and he's not going to change, until he's absolutely ready to do this for himself. I've been in and out of rehab so many times, I've honestly lost count. From personal experience, rehabs will not work unless you put the work into your own recovery and really want it.
I wish you luck in this situation and hope you can find the strength to do what's best for your children. This is not a healthy environment for them to grow up in. *hugs*
-Jess