Hey, I can really identify with the 'missing him' thing. In the summer I went on a volunteer project to the rainforest in Central America which lasted a month and I had literally no contact with my boyfriend for that time- no mobiles/post/anything at all. We'd never been apart for longer than a weekend, but we managed it... coming home was amazing but being apart made our relationship stronger.
One thing which really helped us was: we went out together and bought a note book each before I went away, and then for that month we wrote to each other when we needed to talk and were missing the other one. We also just wrote about what we'd done that day we knew what the other had been doing. Granted, mine was fuller than his was as a) I'm the English student and b) I was the one in the rainforest with plenty of time on my hands. It was really great coming home and reading what he put. He wrote some amazing things that I didn't ever imagine he'd write and I cried when I read it. My book became 'him' while I was out there and it even became referred to in the group as my (insert boyfriend’s name). It sounds really soppy now, but at the time it was such a relief to have that book, it honestly did help.