Teachers of writing, I bear glad tidings: You do *not* have to grade everything your students write. In fact, you shouldn’t.

From teachwrite.org:

Kelly Gallagher, high school teacher, researcher, and author of Write Like This, reminds us,
“Students should be writing way more than a teacher can grade. When
teachers grade everything, the writing pace of the classroom slows down.
Volume suffers. It is only when students begin writing more than the
teacher can grade that they approach the volume necessary to spur
significant growth.” How much writing is this? Gallagher suggests
students should write FOUR times more than teachers can grade.  

Consider yourself liberated, you grading martyrs.