Anticipatory anxiety is often worse than the feared situation itself.

If you look closely, anticipatory anxiety is often closely linked with indecisiveness. That is, delaying making a decision. 

For example, someone who can’t sleep because they fear a big public speech the following day is likely indecisive about getting up on stage or calling in sick. Or whether to read word for word from the script or try to be more natural. 

Anticipatory anxiety often decreases as we start to make decisions about the feared event.