You have nothing to lose, then. Since you still have some sort of drive or sense of purpose to go into your job, might as well tell people what made you hate your job and office and helped push you to a dark place. Not that you'd tell them the heavy stuff, but that open office plans make phone calls hard or raising prices in the vending machines while freezing wages makes you not care if the work is done right. Whatever it is. Might as well make them uncomfortable too, right?
Most people are afraid to speak up. They're sycophants to survive. You could reach a new level of Zen. Let that which truly does not matter, slide.
Kind of like Office Space. Or Fight Club. Depending on your attitude.
You may even pull out if it by changing your environment enough to care about life again. Cause shit man, it can't get much worse if you're suicidal.
Personally, I walked out of a job with nothing in the works because I kept having nervous breakdowns and didn't want to deal with everything anymore. And you know what? I got some much needed perspective in that downtime. I feel much happier now.
Killing yourself means everything else wins. Make life deal with YOU. We all die "naturally" soon enough anyway. My best friend died two weeks ago way too young while shitty people live till they're 80. I don't know when I will die. But I won't stay quiet at my job it's in my life just to prevent making waves. Someone has to make them. Maybe it works out, maybe it doesn't. But damn if it's not healthier to let it out.
. I may not know you, or really anything about you, but I do genuinely want you to stick around. I believe you have the capacity to make the world a better place for yourself and hopefully for others too.