Put down your phone, unwind, and read a book. I always drink a cup of tea before I go to bed, becomes it slows down neurotic parts of your brain, and helps you retain information better for school. Sleep is important, your goal is to get at least 8 hours per night. Phones displace blue light, which burns into your mind and makes your eyes hurt, so a general rule of thumb is to turn it off by 7 at night.
Now, I may be a hypocrite, but I usually have a blue light filter on, and I only picked up my phone now to answer your essential question. Good luck in sleep, and good night.