Wow, I remember this. My fiance just finished his BMQ this summer. I remember not wanting to leave home in case I missed a call. Got over that, though, when I realized I had to live my own life. You should try setting up a calling schedule, that way you won't be as worried about missing calls. Ours was (really early!) Sunday mornings.
I also did cards and scrapbooking! Too funny. I sent care packages of stuff I was working on, which my fiance loved. I also did a little booklet for him, with letters to open at the end of each week, explaining various thoughts on our life together and offering encouragement. And I worked out a lot as I was trying (and am now in) the army, too. I found that I rediscovered my own self as an individual. We've been together so long, that I had forgotten what and who I was without him, if that makes any sense. I'm stronger for it, but I also reaffirmed how much my fiance and our life together means to me. It gets easier, I promise.
I was actually most worried about my fiance coming home and the both of us having to readjust to life together, but my worries turned out to be nothing. Tons of us here know what you're going through, so write if you're ever feeling down.
Take care.