helpp

I need help looking for a manhwa :

I remember it was set in a royalty historical setting and the mc ( a woman) had to marry the ml who suffered from some kind of condition. The mc could like heal the ml gradually from this disease?? At first they weren’t very close but they grew closer over time but healing the ml caused the mc to grow weak and die. then she went back in time and was determined to marry the ml again because they were very in love before