The Fake Hero of the Apocalypse

In Time Travel, the Female Protagonist Is Wiser and Stronger Than the Male Protagonist.

Asking for Books! ! ! !

I remember there was a book in which the male and female protagonists got married from the beginning. It was just a fiction. The female protagonist had a boyfriend outside, was cheated by her, and then accidentally moved to the male protagonist's place. They got to know each other a little bit and fell in love with each other.