No time to be a student

I am so overwhelmed right now. I don't even know how to explain how overwhelmed right now. I just got my review set back, and I can't it hurt. I don't remember the last time I got lower than an A- on a writing. It makes me sick. I feel like I have no time to be a student. I just can' t handle this right now. I love to write, and normally I comb through my writings with a fine toothed comb before actually submitting them, but I don't have time to do anything! I don't know what to do! I haven't got this balanced yet, and I have this huge pile of papers sitting in front of me that need to be read and graded. It makes me feel physically sick. I don't know how to be an "average student"! I really feel like I have no time to do anything right now. How do you balance this?