Sorry you're dealing with this. Life sucks, sometimes. I've been a Soldier over 31 years. We require exceptionally special people to be military spouses. She just doesn't meet the minimum standard. If she can't be faithful while you're pulling a 24 hr duty, she won't be faithful for 12 months while you're deployed or for a few years if you were captured or for the rest of your life if you were seriously wounded. You can't trust her heart, so you also can't trust her with your money or any future kids. Put bluntly, she's got nothing you could benefit from. If you have given her a General Power of Attorney, go see JAG and rescind it. Protect yourself, financially, until you can make a permanent solution.
Sadly, right now, your primary focus needs to be on getting you and your people to Afghanistan, doing your job, and getting everybody home with all fingers and toes attached. You don't need this domestic grief in your head because that will get you or your buddies killed.
It's a very tall order but if you can't get your head in the game and keep it there, you need to talk to the chaplain or a shrink and get pulled from this deployment. There will be other deployments. Don't do something stupid that will cost your career. Over 31 years, I've had three wives. I've had one Army. My wives didn't pay for my college. They didn't pay my bills and they won't be paying my pension. The ones I divorced needed to be divorced and although it hurt like hell at the time, looking back, I realize they were cancerous tumors in their own way. They moved on and made other men miserable.
There are faithful women who would crawl through fire for you. They will willingly go wherever your service sends them. They will patiently deal with the military's special brand of trials, proudly supporting you the entire way. Find one of those and accept nothing less. Once you do find one, never take her for granted because she will be worth her weight in diamonds and more.
Thanks for your service and take care of yourself and your people. Nothing that woman is doing is worth losing a finger or toe on any of you. Seriously! Get your head straight or don't go on this deployment.