@Koreko Here's a tip for your sleeping problem.
Step 1: put phone earphones in your ears
Step 2: start music
Step 3: go to bed
Step 4: close eyes and listen to music
Step 5: fall asleep eventually
Step 6: ...
Step 7: profit
Bonus points if you use a music player like Poweramp, or Vanilla Music that can auto-stop music playback after a set amount of time.
Another tip you can try: get yourself an e-ink device, and read a book or manga until you get tired, when you want to go to bed. Might work with regular screens too, but e-ink is much better.