*Caution - Depressing post ahead!*

With every moment of awareness, there's this nagging thought - that even though things are perfectly amazing around me; there's something fundamentally wrong in me, about me. By what age do people normally become aware of what it is that they want to do with their lives? Because I have no idea what I want with mine! This sense of aimlessness is constantly painful, to say the least.
Not that I'm not doing well enough in whatever it is I do. But when I stop and ask myself, "Is this what I want to do all my life?", the answer is always a No. But the problem is, I do not know doing what could change that answer to a Yes!
Are consultants really wise enough to know what I don't know about myself? Can they help? Or do I just need a break? There's really nothing that seems to be helping me out of this senselessness - no thought sounds thoughtful enough, nothing helps me sustain my fleeting moments of happiness.

Please help! Suggest something/anything that can get me out of this awefully gloomy state of mind. :(