I read this book during middle school between 2005-2009, I got it from our school library. I read it in German.
Cover: I think it was a dark blue cover showing the outside of a house, with a close up of a window with white curtains at night.
Stories: The framing narration was about a boy who was supposedly very sick, being visited by a strange woman he doesn't know, who tells him fucked up stories about death.
The first story I remember the most about cuz I found it very upsetting. It was about a grown man who was some sort of professor, author or scientist? He was bullied at school because he has mismatched legs and walks with a limp, but now he's matured and wants to leave his past behind him and live with confidence. He's invited to give a speech at a school, and while he's doing that speech, one of the kids points out that his legs aren't the same length. And suddenly, all the kids start mocking him viciously for it, and the man starts to see his old bullies in all of them. He can't stop them from laughing at him, nothing gets through to them, and he's about to flee, but spots a fireaxe in the room, and instead locks the door. The story ends with the room suddenly being filled with screams, and then falling quiet. The door opens and the man limps out of it, axe in hand, he's covered in blood, implying he murdered every single kid in the room.
Another story I remember is about a kid stuck in traffic with his parents, he's complaining and being a shit but his parents never turn around to look at him and just kinda tell him that they're gonna be there soon. The kid looks out the window and suddenly sees that the car next to them is being driven by a corpse. He freaks out and starts to realise that ALL cars in traffic are driven by dead people. He then looks into the front mirror of their family car and sees that his parents have gashing wounds on their heads, and they calmly remind him that they all died in their car, and they're on their way to the afterlife. The kid has to accept that he's already dead, and that's how the story ends.
There are about three more sidestories that I can't remember, but the framing narrative ends with the boy learning that he has died, the lady in his room is a vampire who has been waiting for him to turn, and she has been trying to make him accept his death by telling him stories about dying. The story ends with them leaving his window to go hunt people together.