Working in tech and poor self-care

I used to go to the gym 4x a week, exercise just fine, get in my protein intake properly etc. When I started working corp tech -- I just get consumed by projects and deadlines, working overtime , hours on end without getting up AT ALL. As a result my blood circulation is terrible and my pelvic muscles are insanely weak. 

I've been exercising ever since it worsened to combat it finally lol. Also been setting timers every 30 m to stretch, drinking more water and going on an at least 15 m walk at 12pm regardless of whatever Im doing. 

However, I make this post to ask -- is anyone else in the same position who works in tech? If you overwork like this too -- what are your reasons for doing so? Am I insane for enjoying the mental stimulation and working on things with such vigor, or am I just an idiot who's gonna die from poor health soon?

Sometimes idk if its my perfectionism, genuine interest or fear of losing my job if I dont excel/reach deadlines thats making me pull these all-nighters/late nights and crazy hour days. 

I used to be the same when I worked in other industries, overworking that is -- but that was because I needed the money. In this instance, what am I killing myself over? Idk