Responses
This maybe?
https://www.mangago.zone/read-manga/the_blooming_flower_in_the_palace_is_crazy/
I just skimmed the first few chapters but your first paragraph matches.
Yaass!! This is the one! Thanks much! You're an angel~~
It's a bit unpopular so I can't find the title. It was a historical setting. I'm just not sure if it's Chinese of Korean. Buut the crown prince is in love with another person. I think she's a woman from a brothel. Her hair is silver and she's a white lotus. Then the crown princess is chosen sooo he (the crown prince) said that he will never sleep with her blah blah cuz he's in love with the concubine.
But the concubine was disposed of pretty quickly and the story focuses on the fight for the throne with his brother from a different mother. I think the brother is in love with FL and at the end he killed himself and the guard of the FL is kinda in love with the brother prince