What's a grain of sand in the hour glass

So i was a bit, and still am, disheartened by this one class. It has me shook a bit because the exam grades are not in my favor. Granted there are 3 more assignments, but still when will the uphill battle turn in my favor? So then i started thinking, i'm sure this happens to a lot of individuals. I'm sure that i will succeed because i cannot quit.