He asked for a break

Caroline • Marine girlfriend 🇺🇸❤️, special education teacher 💛
Hey y'all please hang in there with me, this might be a novel. 
  So my boyfriend is a marine who is currently deployed to Afghanistan. We've been best friends for about 9 months and dating for a little over two months. I knew this was going to be a strain on the relationship but we work really well together so I knew we'd be okay. We were really lucky to have great communication, we text every day, Snapchat, and when he has time he calls. 
    The first month of deployment went as well as it could! I supported him with everything and I just tried to be there for him. However, this deployment isn't really going how he expected it, and he got some tough news that they would be extending his time over there. This really threw him for a loop which I understood. I gave him the time to be upset and annoyed, but he never snapped out of it. He's been distant, not interested in conversation, and not affectionate at all. He made me feel stupid for missing him. 
    So after two weeks of him just being off, I asked if we were okay. He said he thought so but it wasn't reassuring. We had a conversation about us, and it resulted in him asking for a break. His reasoning behind it was that Afghanistan makes everything much harder. He told me he doesn't really know what he wants and that he needed time to think. Even though I was heartbroken about this I agreed to the break. This part might be silly but he posted to instagram the other day a picture of all of his friends and him from high school and how he wished he could be with them. It really hurt because it felt like he was living life as usual. 
  We agreed to a week, but I'm really worried that he might just want to end things. I love him a lot and I want to work this out. Has anyone been through this before? What should I do? Thanks (P.s you're amazing if you read this entire thing)