I just got your email. Im really sorry to hear that you have exam stress, dont worry though i can help you and give you some advice.
You could take regural breaks, watch a film or a TV show that makes you laugh, take a shower or a bath to help you relax and relieve stress, look forward to doing fun things, avoid other stressed people and write down everything you feel like you need to do and try and tick one thing off. just the act of feeling like you are in control of your revision can help.
I hope my advice helps.