volunteer for a charity (i.e., a soup kitchen, reading books to children, etc.) makes you really appreciate the fact that, while you may be single, you are still better off than some folks are.
another option would be to host a holiday dinner for some of the people on base who cannot get away for the holidays to be with their families. We used to invite the younger airmen from our base via the first sergeant (not sure what the navy equivalent is) and have them over for dinner. usually made some new friends that way, too.
the key is to remove the focus from yourself to others.