Depression

So July 17 2016 ( This Sunday) my boyfriend of 2 years is leaving to go to the Marines and he's already started pulling away and acting different almost to like prepare himself for not be able to talk to me for the next 12 Weeks during training. I'm starting to suffer from depression because while I just want to be up under him and get as much time with him as I can before he goes he's pushing me away & I'm getting depressed just thinking that starting Sunday I won't be able to see or speak to him for 12 weeks. It's going to be a weird adjustment because either I call him in the morning to wake him up or he's calling me. We literally talk all day long, if we aren't on FaceTime together then we're together. The moment I leave he calls me or I call him we just enjoy talking to each other that much and on Sunday it all changes I just don't know what I'm supposed to do once he's gone. Sorry it's so long trust I can go on even more but that's pretty much the cause of my depression. 😒