All I can say is that I'm about 4 or 5 years out after being about 4 or 5 years in. And the emptyness didn't go away until I got married a year and a half ago, and really tried to change my life. I'm not saying you need to make a drastic life change. I'm just pointing out that what you feel is very normal given your time out after so much time in.
Good luck - Will