One way to prevent anxiety from getting out of control is to recognize its benefits. It is a mistake to think that we'd make better decisions if only we keep our feelings under control. Instead, a mix of feelings like anxiety and logical thinking leads to sound decision-making. It's true that there is plenty of research showing that higher levels of anxiety can make us more likely to avoid risks in our decision-making. There is also evidence that anxiety can increase the attention you pay to relevant information.
Recent studies have shown that people who are anxious about their relationship (for example, they fear to be abandoned) tend to be better at recognizing people who tell lies and are more likely to raise the alarm when danger is present.
In the real world though, it's worth realizing that feeling anxious once in a while is extremely common. It communicates to others that you care, and what's more, it's probably a sign that you are intelligent. At least two published studies have identified that people who score higher on measures of anxiety also tend to perform better on intelligence tests. This seems reasonable: if you're a thinker, you are sure to be always thinking about the future and imagine possible plots, including bad ones.
The important thing, if you are a worrywart, is not to let your fear destroy your dreams. And don't bury your head in the sand Instead, act on your fears—do the research as well as preparation, so rather than walking blindly into that which you fear, you meet the challenge in full readiness.
When anxiety beats you, or casts a shadow over your life, this is a serious problem. No one is denying that. But like everyday anxiety of this kind that you feel before a presentation or an interview, you needn't see it as your enemy. Anxiety is an important feeling, developed through evolution. As for people who are fairly anxious by nature, there is reason for cheer, too. Your nerves are a sign of your watchfulness.
Listen to them and act on them. Then you can turn your nervousness to your advantage.