Rising Reign by Tessa Hale

Love means sacrifice. And that's what I've done: given everything to keep those I care about safe. Now, I'm back where it all began, trapped with the architect of my nightmares. And this time, I know he won't stop until he breaks me. But my wolves won't stop either. They'll do anything to bring me home and end the one who has me in his sights. Only there are more monsters and enemies than we ever could've imagined, and when new secrets are revealed, it will take everything we have to defeat them…