What are you worried about? Is it something that happened long ago, or an imagined future that is causing you angst? Either way, you're wasting your time and energy. The Power of Now shows you that living in the moment is all that is possible. It demands that you ask yourself, "What is happening right now?" Nothing can take place outside of the Now. Anything else robs you of the reality of your life.
Anything you have to handle will present itself when you need it.