Whenever I started getting anxiety over an upcoming exam, after I've done my studying, I put everything I can remember on a huge piece of paper or a board (i prefer chalk). Then whenever I look at the mural of information I feel ever more confident. Just keep cool and do things that will boost your confidence like taking practice quizzes. Also, I found it really helpful to chat with the teacher. Usually, they will drop hints for ya (if they are nice) or give you confirmation on whether you are ready or need to study more.
