exam stress- i'm not ok =(

I seriously can't take this anymore.

So I'm doing my AS level exams. There's eight in total, over the course of two weeks. I've taken two already (pyschology), and my next exam is tomorrow morning, 9am - English.
The pressure's crazy.
I've been good at english all my life, so they're expecting me to get an A... but I just don't think I can do it. I can already see the dissapointment in my mum's face. I can already feel the suffocating, crushing feeling of dread when I go to pick up my exam results.

Why is it that we're all defined by our academic achievements? Some of the richest people in the world dropped out of college- look at Richard Branson or Sir Alan Sugar. Yet if you don't have the right qualifications in life you're automatically classed as a second class citizen.

The only way I'm getting through this is by listening to MCR.
I'm not OK...
HELP!