Haha I loved your description.
I don't really have any study tips just keep your goal clear and simple. And keep a goal at the end of each task for eg. 5 minutes of break or a piece of chocolate or 10 minutes of using mobile.
Drink lots of water to keep yourself awake. Plus, do lil exercises in between.
ANYWAYS, I just noticed, you are 69 and a student. BTW, that 69 number ( ͡° ͜ʖ ͡°)
At last, 보라해 and take care. ♡