I had a job running a tech department on a small company. It was my first management job and I wanted to make a success out it. The company was pretty dysfunct

I had a job running a tech department on a small company. It was my first management job and I wanted to make a success out it. The company was pretty dysfunctional and I took it upon myself to pretty much do everything, so much so that I was working 12 hour days (This is work time, minus breaks, measured with an app) so my day would start at ~ 06:30 and finish ~ 21:00. I have never been quite so miserable in my life and I was making so many mistakes that it was unreal. I also picked up a very bad habit of doing things quickly and 90% there as that was better than not doing them at all and to do them properly would take too long. It's been close to a year now and I still find myself falling in the turn things around quickly and sacrifice quality trap, even when there is no rush at all for it. I hope I get rid of this bad habit soon