Lover Eternal (Black Dagger Brotherhood, Book 2) by J.R. Ward

Within the brotherhood, Rhage is the vampire with the strongest appetites. He’s the best fighter, the quickest to act on his impulses, and the most voracious lover—for inside him burns a ferocious curse cast by the Scribe Virgin. Possessed by this dark side, Rhage fears the times when his inner dragon is unleashed, making him a danger to everyone around him.

Mary Luce, a survivor of many hardships, is unwittingly thrown into the vampire world and reliant on Rhage’s protection. With a life-threatening curse of her own, Mary is not looking for love. Her faith in miracles was lost years ago. But when Rhage’s intense animal attraction turns into something more emotional, he knows that he must make Mary his alone. And while their enemies close in, Mary fights desperately to gain life eternal with the one she loves…