Before the exam : Insomnia, less (or increased) appetite, or inability to concentrate. Boredom may also be a symptom of anxiety. A surface lack of interest in a subject may cover a deep-seated anxiety about future performance. There may be mock indifference (don't care attitude), guilt, anger and depression.
During the exam : Confusion, panic, mental blocks, fainting. Think about the reasons for your anxiety and write them down. Consider each reason very rationally and objectively. Write down the worst that could possibly happen e.g. "
If I felt embarrassed, then the worst that could happen is..." By spending some time analysing each cause of your concern, you will come to realise that in fact, there is nothing that can damage you permanently if you do happen to fail an exam. Lots of students have failed. It does not mean they give up. Many students who fail return with a vengeance and perform very well — they are the survivors in life ! They make a new plan when the chips are down.