" I stay up hours later than I mean to, not even doing anything, just trying to put off sleeping — because the next thing I experience will be waking up and going back to work."
This is straight up depression. We need to stop using office-cliches like "burnout" and start addressing the very real mental health issues in the tech industry. Maintaining my mental health is like staying in shape, eating right, etc. Only as an adult have I learned how much work it takes to stay mentally healthy and not fall into these traps. Things like pacing yourself, recognizing when you're stressed, being able to say 'no,' taking enough breaks, having a dialogue with your boss/clients on what your realistic expectations should be for this project, self identifying with your job too much, not having outside interests outside of tech, etc all matter.
Techies seem to love stress. We're competitive, asocial, difficult, etc. No wonder stuff like this is so common. How many high profile tech suicides have we had in the past few years? We're doing the opposite of staying mentally healthy. Turns out human beings are incredibly delicate creatures, but no one wants to admit it as to not look "weak."