We exist because there are certain karmas we need to work out. Karmas are energies that are concentrated around one point: an individual personality. We need to let go of these energies so that we are free from them. And then, we need to make certain that no more karma accumulates around us.
The best way to work out our karmas is to allow life to put us wherever there is a need for our talents. Talents are survival skills that nature gave us so we can continue to exist.
And, the best way to avoid acquiring new karmas is to perform all your actions in the spirit of selfless service to all. Offer your actions up as a prayer to the divine. Be humble when acting. Be respectful. Be conscious of the input your actions have on you and on your surroundings.
So, stop the worrying and constantly projecting mind and flow in the beauty of the moment.