Three very creepy stories about curses from the creepypasta library.

A Curse Cast Once, Turns Seven Time
Dthdsguise
https://creepypasta.fandom.com/wiki/A_Curse_Cast_Once,_Turns_Seven_Times

The Curse of the Ninth
Trycksterr
https://creepypasta.fandom.com/wiki/The_Curse_of_the_Ninth

Curse of the Funeral Flowers
Shaherrrb
https://creepypasta.fandom.com/wiki/Curse_of_the_Funeral_Flowers