Dying bisexual

Guys I need help, I am looking for a manhwa where the fl gets transmigrated into this empress who is married to the emperor but she has a harem that she abolished as soon as possible but there was this blonde guy who wouldn't leave cuz he was promised scholarship money for the academy in exchange to be in the harem. When she talks to him she realises he's really smart and works with poison and she makes him her personal doctor because she wants to build a tolerance to poision. She then goes and make the emperor fix his schedule by accompanying him to breakfast lunch and dinner. To collect poison the blonde guy tells her that hair is really good for it so she starts brushing the emperors hair and later there's a party type thingy(I forgot what it's called) and she brushes her hair then too and everyone is like omg what is she doing and she tells them it helps her relax and everyone is like we wanna try and she has people bring in brush and then she brush their hair and the blonde guy makes poision with it and she takes it and coughs up blood. There's also stuff going on where we realise that the og empress was under black magic and there's a cousin who looks exactly like her but with shoulder length hair. Her hair is like white/silver and the male lead has black hair from what I remember. She wants to get a divorce too btw. I BEEN TRYING TO FIND THIS FUCK ASS MANHWA FROM 6PM IT'S 4 AM NOWI AM GOING TO DRINK POISION MYSELF IF I DON'T FIND THIS THING BRO (my apologies if there's any mistake in this post cuz my braincells have died)