Read The Law of Love in the Last of our Days Manga:
Mu Yiran, an orphan girl, died with hatred in the post-Apocalyptic era.
After getting a rebirth by chance, she goes back to three days before Doomsday. In this life, she has managed to deal with the mistress and the guy who two-timed her. She has got a space for immortality cultivation and uses it to stock as many supplies as possible, but accidentally, she offends the strongest more.. marshal of the post-Apocalyptic era.
“Girl, you have no way to run!”
The romantic story between the stone-faced marshal and the girl who is an immortality cultivator therefore begins.