Introspection is good as long as you can bring balance back to yourself. Like Jerry said, a heart-to-heart talk with yourself and then become happy again. We all hit some down spots in our life George it is up to us alone to bring us back and find peace and happiness within.
At a certain point in life this kind of thoughts crop up every so often. I used to feel pretty much that way until October 2011 when I had had a heart-to-heart talk with myself and since that day I have never been happier. I'm happy I lived long enough to see that day.