I really need help plz!?

i have a very imp exam in next 5 days,this exam say that which fields you can study in university and which university you can study.my family think that i would have a very excellent degree in it,i have studied very much too,but i am full stress and i am afraid that i dont have a good exam,i am realy under presure,i fill so depress.what should i do?oh my god