Is there anyone who has been doing well in the exam, and suddenly the exam is particularly bad, unexpectedly bad?

Take me for example, my previous grades were top-notch in my class and the whole grade, but I failed this midterm. Emm is not afraid of jokes. I only got 95 points in math (full mark 120), and even my best history was only 87 points (full mark 100). The others haven't come out yet (I took the exam yesterday and the day before yesterday). Just cheer up next time, but the more she says I feel guilty, the more guilty I feel. I can't imagine how to face my teachers and classmates. They all have high hopes for me. I feel sorry for my parents, too. I feel very indebted. I want to cry, but I just can't. Now I'm particularly afraid of being asked about my grades. It's really a collapse. I also want to try to adjust my mood, but I can't.