dear leo,
long time no see.
I heared you in bad mood because of the exam.I'm sorry for it,but don't worry ,Ican give you some advice,hope can help you.
At first,you should relax yourself.When you tired of your study,you can play some sports,which can make you more energetic.Also you can listn to somr music,which will calm you down.Then make your best to master what you study.
I hope you will do well in this exam.
yours
Wangpeng