You can only manage what you do & when you do it.
If work is piling up, you're probably spending a lot of time on unknowns, and not enough time each week doing your work. That's what Weekly Planning is about.
If you are finding that you suddenly have multiple exams and papers due in a single week, and no time to do them in, you need to go to the page called Syllabus Mapping.
If you are feeling overwhelmed by the number of different tasks you've got, or you find yourself putting off tasks, you need to work on making priorities.