That was where I was at not too long ago. Working 2 jobs, barely sleeping, completely neglecting all healthy habits. Sometimes I'd have back-to-back-to-back 18 hour shifts and I don't really know how I managed to keep it together. My brain was in some kind of primordial survival mode where I was just focused on the right then and now at all times. Hard to live life that way.
Ironically enough, the reason I worked so much was because I actually was suicidal and needed something to take my mind off of it. I lost a year and a half of my life being a dissatisfied grunt, but it worked as intended, and now I have a healthy financial cushion should I need it.