What happens next?

How to deal with exam stress
Know what is expected of you.
Be sure to consult your syllabus or ask your instructor what material you will be responsible for. If you have a concrete sense of what you will be tested on, the future test will feel less vague and more like something you can handle.
If you aren't clear on anything, ask your teacher. Teachers would much rather answer questions than have their students proceed without understanding what's expected.