Feeling really really down

It has been a long time since i last feel so scared on an exam results....i checked the answers and the way i wrote the exam is one of worst in my life....i am so afraid that i'll fail it...I swear i studied for it but things just not going my way....i am really really scared that i won't pass this exam...i am waking up with palpitations and tears every morning......what a torment...please....i have to pass this exam.