This book is on pre-order until book delivery arrives. 
 
Beneath the Starlit Sea (Fairytales of the Loch #1) by Nicole Northwood:
 
The best way to understand a monster is simply by listening to their story.

When sorceress Illyse is pulled into a conflict amongst those with magic and those without, the last thing she expects is to develop feelings for one of the humans supporting the king. Dragged into Castle Thorn by the royal guards and coerced into helping with a monster hunt under the guise of a thousand-coin reward, Illyse reluctantly agrees to tap into her abilities.

Garit is a medical practitioner and a mystery unto himself, determined to finish his royal service contract before leaving the kingdom of Moningrad behind for good. After his partner was killed by the beast in the Kincade Sea, he stopped believing in the power of love or enchantments. But when Illyse appears at Castle Thorn with knotted hair and shackles on her wrists, Garit realizes they’ve met before—and that emotions and magic might not be as horrible as he’s thought.

As Garit and Illyse hide their forbidden relationship, it isn’t long before they must decide between duty, desire, and the decrees of a king who might be more interested in wielding power than serving his people.

Beneath the Starlit Sea is a standalone fantasy romance with alternate historical elements and atmospheric storytelling. If you've ever wished for The Witcher as an age gap romance between a human and a sorceress (who is paired with a sweet fox familiar!), then you’ll love meeting Garit and Illyse.

Content warnings can be found on Nicole Northwood's website.