No sure if there is "professional" advice on this that can be truly effective. Sure, there's counseling but I think it's still someone telling you what they THINK you should do. The only person who knows is you, and you alone.
The reason I know is because I too am in the same boat, but the concern is more focused on career. I have been in the same line of work for a while now, but it does not give me much stimulation in life, and I'm sure I do not want to do this until I retire. That is probably why I am on this forum in the middle of the day!
One thing that has changed my mind in the last ten years is my view and opinions on senior citizens, especially the successful ones. In my youth, they were just grumpy annoying people, but as I matured, I realized that they have a world of knowledge, and many are kind enough to share their thoughts and experiences on life. So my only advice is to seek older folk and get opinions from them. After all, they've been there.
In the spirit of lstream's link to Steve Job's speech, here is
Conan O'Brien's. It won't help your problem, but I promise you'll forget all about it for about fifteen minutes. Good luck to you.