My grades went down and I'm afraid to دکھائیں my exam results to my parents.What should I do?

دکھائیں it anyways. Grades aren't everything and your life isn't over. If they're mad, they're not going to be mad at آپ forever, in fact, its nice they care about your education. Its better to deal with the disappointment now than worry about it any longer.
It might help آپ to study now for the اگلے exam.

trust me im sure your score beats every score I ever made so im a natural disappointment be lucky آپ arnt me XD im sure آپ did fine

دکھائیں them the results. They'll find out somehow anyway and it will look better coming from you. Try and explain why your grades went down - have آپ been having difficulty in lessons?