I'm not coping.

I'm in the 9th grade, and I have exams coming up. I'm studying and I'm one of the best students in my class. However, due to the large number of assignments in non-core subjects, I now don't have enough time to eat and sleep. I sleep 4-5 hours a day at most, and I eat 1-2 times a day. At the same time, I study in a math class, but most of my energy is spent on humanities. What to do?