Dear David,
I'm sorry to hear that you fail in the final exam.Well,please calm down and don't be upset anymore.I have some good ideas that may help.First,why not review the books carefully?It is very important to review the books before taking an exam.Second,you'd better ask teachers or classmates for help.They are also good for your studying.By the way,you can also call me for help if you have some trouble in studying.In this way,I'm sure that you can catch up with your classmates at once.
Yours
Martin