The mood for doing school papers

I can't mantain focus to do my school papers. The only things that works is somewhat harmful for the body. So much that I get all sore and anxious when I try to achieve it. It's usually sleep deprivation and overexhaustion. Like 36+ hours without sleep. And then gurgle caffein, not too much, because I will shake too much, not too little because I will fall asleep. That's the only thing that ever worked for me. And I refuse to do it anymore. What are some healthy habits to achieve the same?