Ok...time to play momma here...
You are NOT gonna fail!!!
here's what i think...for what it's worth lol...
1. beating yourself up over it and worrying about it just makes it worse.
2. you need to break up your revision times...i got told take 10 mins off after every 50...go have a coke, send a friend an e-mail, listen to a song and give it your undivided attention, whatever works for you.
3. don't forget to give yourslf decent breaks like you get in school...schedule your revision time at home the way schools schedule your study time. i.e. ...give yourself a recess time, a lunch hour etc.
4. believe in yourself. give yourself positive affirmations to repeat to yourself every day like a mantra. believe it or not it does work.
5. don't forget we're all rooting for you coz we al believe in you.
6. you go girl, you WILL pass those exams.