PLEASE HELP

Okay so i’m trying to find a manhua/manhwa i’ve read but i can’t seem to find it T_T
I believe the FML has red hair and she and the ML have been forced together. One day she falls in love with the white haired knight (slergy(his name is something similar)). However the ML sent slergy to fight in the war (?) and he died. Depressed about her lovers death she vowed whoever the ML falls in love with, she’ll kill them as revenge. Sorry for bad explanation :(