Oof, here's one that I remember and that people witnessed.
It happened when I was about... 12? 13?
I was being relentlessly bullied by some fucking asshats. They spread the rumor that I was cutting.
One of the motherfuckers had a Swiss army knife cause he thought he was a badass. I was having a really shit day already, my family yelled at me for some stupid shit, my cat got sick, I was sick, and I'd already dealt with several of this dumbass's friends, not to mention another failed history test.
He decided to taunt me with it, can't remember all of what he said but it was along the lines of "don't you wanna cut your wrists, you fat emo piece of shit?"
I just had enough, I yanked the knife out of his hand and stabbed myself in the wrist with it. I then ran away and broke down. First time I ever did anything like that. Almost hit bone, had to get stitches. Got found looking like a mess by this gym teacher in the bathroom.