It's a useful feeling at times, because it can help you identify what or whom you are missing. Sometimes I have found it is a part of myself that I need or wish I had, sometimes it's a specific person, sometimes it a general sort of person to fill a general place in my life. While you're lucky enough to have the feeling and be aware of it at the same time, you can ask it what is it that you're missing and what you'd like to do about it and often, if you're willing to listen to your own answers — and I mean, take time and listen to your own answers, you will surprise yourself. It is the taking the time to listen that's hard.
Get a notebook, if you're a diary kind of guy. This is a good use for them.
All my best, Bob Kaven