Help me find this manhwa

Anybody know this manhwa, where the fl (i think she got blonde hair) she's kinda sick (?), and she was transmigrated i think. She tried to propose to her fav character which is the second lead of the og story. The ML got black hair, he's buff (AND ALSO SOMETIMES WEARS YK SOMEKIND LIKE CORSET WHICH IS VERY ATTRACTIVE) PLS ANYBODY KNOW THE NAME??? I HAVEN'T CONTINUE THAT MANHWA HELP ME