I'm dead~!!

I'm going crazy this few days. We were having exams. I studied at the last minutes then I need to stay awake to study in the midnight. This makes me very tired and exhausted this few days. I only slept for few hours a day. Plus my stomach is not feeling well; don't know what the reason is. I have no appetite to eat and can don’t eat for around 20 hours and I won't felt hungry. Everyone says that is good because I can keep fit. I think I'm having too much stress. I worried for my exams, feel like I will fail in this exam. I hope there's some miracle. I will be crazy for the rest of the days because the hardest subject had done. I regret to choose to study quantity survey. I think it doesn't suits me.