A Dying of Starlight by Alex Nonymous

The Last Princess of Rosenly is dying. Born of a wish made upon a star, she's spent her life kissing strangers in a desperate attempt to find her true love and anchor herself to the earth before turning eighteen. What only she knows, however, is that no kiss will save her. The Last Princess of Rosenly realized years ago that she will never fall in love; she wasn't built capable of it. When an assassination attempt leaves a wound on her throat and a Wish Weaver in her dungeon, The Last Princess of Rosenly allows herself to hope. Maybe the stars have finally decided to send her a soulmate after all, with two months to share and an unwavering animosity between them. The prisoner is going nowhere. She'll reform her, she'll kiss her, and then, she'll save an entire kingdom.