The more you focus on any possibility, the more power and substance you give to it. It is by giving your persistent attention and energy to these possibilities that you make them real.
The same dynamic works for both the desirable and the undesirable possibilities. Whether you strongly fear or strongly desire, the power of your unrelenting attention will work to create whatever you focus upon. Choose, then, to make your focus a positive one. Instead of living in fear of the bad stuff, live with a persistent desire and appreciation for the good stuff.
Be sincerely thankful for the goodness you already have, and your gratitude will create even more. Imagine in detail how your world can be a better place, and your time and energy will go toward making it so.
Not only does fear itself bring you down, it also enables you to bring yourself down. Prevent all that not by avoiding your fears, but by turning your attention to their positive alternatives.
Your attention has great power. Remember always to focus that power in a desirable direction.