It's the climax of your school career, but don't panic if it all goes wrong- life goes on of you don't do well (or even fail!)
You can always redo exams, so don't let results overwhelm you. If you or one of your friends writing matric seems to be depressed, make sure you tell a teacher/parent/friend, and don't suffer in silence.
Talking about it takes the power away from it. They're just exams, whether you ace them or struggle with them- they needn't define you. Be strong and brave!