Look for your professors cues. Breakfast- get up a little early, eat something, anything. You will have more energy and be able to think clearer. Statistics show breakfast can make a 3-5 point difference on test scores. A heavy lunch may make you drowsy and sleepy.
Test anxiety can be a real problem.
It can cause mental blocks, confusion and blow your train of thought. Close your eyes, breath deep, roll your neck, and let your tension go 2. Skip the questions you don't know, you can come back later 3. Review the material you do know in your head. Ask permission to get some water or sharpen your pencil.