The Dragon's Contract Bride

Anastasia married Dmitri and used her magic to put him on the dragon throne. He and her own sister turned on her, and she was left in prison, where she cast a forbidden spell as she was dying. Humans and dragons live alongside each other. Dragons can take human shape but turn violent, and they need the magic of human women to hold the frenzy down, so the candidates for Dragon Lord make marriage contracts with the daughters of the strong magic families. Anastasia was born into one of those families with a great deal of magic, which is why Dmitri came to her. The spell puts her back on the night before Dmitri proposes. She has the whole of the first life in her memory, and she intends to break the contract instead of signing it and to go after the people who destroyed her.