I agree with Derby as far as having your own stuff to do. I am her girlfriend and was her distraction for some of those harder times.
It seemed to help to have a set time to check in also. When those check in times are respected it seems to be only a matter of time that the brain turns off and getting about the business of living takes over until it might not be necessary any more.
It is harder when you and he are in different places for such a long time. Maybe setting a skype date for the week after to have dinner together or whatever would help you have something to look forward to in terms of connection time?