Yikes! That IS a hard time :( I'm very sad to hear of the passing of your grandmother. I related to you in a few ways, one being that my grandmother raised me, and passed away a few years ago. It's so hard, like losing a mother. But she gave you everything you need to be the person she would be proud of. The things you do from here on are a tribute to her love and guidance. It's very hard to learn to live with losing someone so close. My heart goes out to you.
My husband is in the military also. When I was pregnant and having a mental relapse of sorts he was sent to Virginia for a month. It was so hard for the first little while, crazy snowstorms that confined me to the house - ahhhh! I was only able to talk to him every 4 or 5 days for maybe 15 minutes, so to get me through it, or rather, because of it..and conveniently getting me through it... I tore the kitchen / dining room apart. The second I could leave the house I bought paint, new handles and knobs, and new curtains. That was what I did for the following three weeks - completely redecorate the kitchen and dining room by myself.
Added bonus - oh the pride you get along with it!
You say you have a little girl. Depending on how old she is, you could take this as a great opportunity to have some mommy - daughter fun while daddy is away. Do things that you can show him when he comes home. Go do girlie things together. Or, if she's only little, just play! Her laughter will help to ease the pain of your loss.
Concerning your best friend, you were a little vague on the details. "because of her fiancee". Is she allowing herself to be controlled by said fiancee? Is he sick? Are there money issues? Is he jealous? Is she jealous and neurotic and can't leave him alone for a week without her watching him?
Also, thank god you weren't hurt in the car accident. Big huge blessing.