The main method of overcoming fear and self-doubt is "gradual load." The essence of the method is to act gradually. If, for example, a person is afraid of heights, and even can not think about air travel, it is not necessary to start with what is scary to do. To start with any minimum increment – say, up to the fifth floor, walk up to the window sill, to make sure that everything is in order and to carefully watch out the window. The same with the preparation for the exam, the more you train, the easier and easier it will be on the actual exam. So take the practice tests and decide, decide, decide. First, just train to solve tasks of different types, then do it on time.