We all experience anxiety in times of uncertainty, although some of us will express it or be overwhelmed by it more than others. Appropriate anxiety and fear are important reactions necessary for our survival, as they alert us to potential danger and warn us to pay attention to our physical surroundings or current situation.
Becoming overwhelmed by such emotions, however, is usually counterproductive to good decision making and effective communication with others. Moreover, if you only focus on fear and the worst possible outcome, life can become unbearable.