I totally understand how you feel. I think about it 25 times a day or more. I get up in the morning telling myself what horror I am on earth, realizing that I was dreaming all night. Standing up hits me hard at reality. Then on the way to work, I constantly tell myself that it would be better to throw myself under such a car or such a train on the way to work. When I'm at work, I feel out of place, when I make a mistake, I don't care and I tell myself that I won't stay on earth for long anyway. And it's like that, all the time, all the time. It never leaves me, it's horrible.
I have the impression that I have one year left to live, that I am at the end of my life, like a terminal phase, and that despite all the occupations that I can find, it is obvious, it is my destiny, it is inevitable.