We Agreed You'd Overcome a Love Tribulation, So Why Has the Divine Lord Fallen for Me?

The Female Protagonist Is a Princess of a Fallen Kingdom

I want something similar to Tragic? After Her Country Falls, She Becomes the Enemy Nation's Little Ancestor! The heroine's country treats her terribly, so she has no sense of belonging. The male lead destroys her country but dotes on her constantly. No angst before sweetness: I want it sweet from beginning to end.