Consternation is a noun that can stop you in your tracks because it means "a sudden, alarming amazement or dread that results in utter confusion; dismay."
If you have a sense of consternation you have become afraid, disoriented, or completely befuddled. It comes from the Latin roots con- and -sternare, which means "spread out." Picture all of your thoughts strewn about, nothing makes sense and you might experience a state of consternation. Like the nightmare about the class you forgot to go to in high school and now you have to take the final exam!