I'm sorry to hear about your struggles with this situation. You've got a lot of questions that deserve answers and you should be able to sit down and talk this out with him. On the short end, in regards to you stopping drinking... I'd suggest you do in order to be supportive. I think it would go a long way to saying that you are in complete support and you want to actively participate in his recovery, sobriety and have a healthy life with the man you want.
Recovery is a life time commitment. It just doesn't happen in a day, week or month. What happens is one learns how to cope with the addiction and is taught tools to help cope. For an addict, the addiction is always right there, hiding right around the corner. It is something that most addicts have to fight every single day.... for others, the fight isn't nearly as rough.
As for getting help for yourself, Al-Anon does wonders teaching loved ones of addicts on how to cope and teaches you better to understand what your loved one is going through.
You mentioned that "all I feel is anger". I don't think that is selfish. There is a lot you don't understand and that is enough to make anyone angry. I'd be a little angry too. I can tell that you feel a bit abandoned or alone in this as well. I understand that too, but there is help out there for you. Al-Anon is one option and there are others, but the help you get will better prepare you for the long battle with him, dealing with addiction.
I don't want to direct attention away from you, because you are the one reaching out, but I'd like for you to try to imagine what he is going through. He is probably angry because he feels like he is letting you down, the kids down, other family down plus letting himself down. Who knows what emotions are running through his mind....
Strong couples find ways to work through things and this is something you guys can accomplish together.
Your anger is coming from the fear of the unknown right now. I would hope they will have family time at the treatment facility where your husband is at. I know it feels like you are being shut out right now so while your husband is gone take this time to educate yourself on addiction. Having the support of a loved one is a huge plus for both of you. You spoke of what you can handle such as deployment. You can handle that as you know what is all involved with that. Addiction can be the same way. Alcohol tears families apart, recovery puts them back together again. Keep posting here as we are here to help you~