Responses
https://www.mangago.zone/read-manga/when_the_villainess_loves/
I think you're looking for this one. Not entirely sure though since I lost interest in it once the ML came into the story and all the other characters were sidelined.
Oh thx so much it is the comic I've been trying to find
So this manhwa is about a girl she reincarnated and she became and princess but she kept vomiting blood but she's actually fine and it's normal , MC has purple eyes and white hair