I was in your exact possition about 6 months ago, less than 4 months into a year long deployment there were 'issues', when it was brought to light many things came out and it only got worse, luckly she wasn't cheating, luckly I have some good bro's to do RnS, most of the issues span from us both being active duty military, at that time we had spent 2 weeks together in 10 months, I'll be home soon, after haveing had 4 weeks together in 18 months... it's rough, when I was on R&R she went for the door and then decided it wasn't the way to go, I've had the divorce paper work drafted as well, I've spent over 2 years of my life away from her just from being in Iraq, she's spent 14 months here. Life is rough, but I have 7 years married to her and 9 of knowing her, new changes came to our lives and a move across country, that has resparked alot of adventure.
If you don't have children or a house, it makes it easier to walk away, but that's your choice, she's doing time with out you just as you are doing time over seas, plenty of us make it, over half of the others divorce. You can make it work if you both put the effort in, but it takes two.