Purposeless

I really hate getting old. I know I'm not the first person to express this, but lately I just feel so purposeless. I mean I feel I have a lot to contribute and learn, but I don't feel special. Maybe because there are so many of us "40 somethings" around. We're not starting and were not ending, we're that place in the middle that no one really asks about. Uggh! Maybe it's hormones, but lately I envy the 30 somethings. This is awful, as a therapist, how can I encourage others that they are valuable despite the lack of luster of the outside appearance or the deteriorating of the internal parts and workings. And I know all of this stuff! So maybe it is hormones, but I really feel "dated".