a simple way to pace yourself and not get overworked
https://hjalmarsnoep.github.io/pacer/
Very simple- set break time, set active time, press start.. That´s it. IT will flash red and green and give you a (soft, nice) audio cue. WOrks on a phone too..
Close your eyes and listen to your inner radio on break time until the sound chimes again, then continue. Mini breaks have been proven to increase productivity