Unexpected Mates by Grace Brennan

Tyler MacKeltar has a motto: Just make it one more day. He fights his inner wolf for control every minute of every day, certain he’ll need to be put down at any moment. Life has dealt him more than his fair share of blows, and damaged his animal, almost past the point of no return. He believes nothing can save him, and he knows he’s running out of time. Then Parker Leighton walks into his life. One look at her is all it takes to soothe his beast in a way nothing ever has. She’s human, though, and he knows how that usually ends: in heartbreak. How does he tell her what he is without making her run from him and sending his wolf spiraling out of control again?
Parker Leighton does her best to hide from the world. Shy and awkward, she’d rather be at home with a good book than anywhere around people. Returning to her hometown for her sister’s wedding is torture; until a chance meeting with Tyler has her suddenly eager to be around someone else for the first time in her life. His effect on her is instantaneous, calming her and putting her at ease around someone other than family, when she never has been before. But how can a man like Tyler ever really want a woman like her? And can he handle what she needs to tell him?

One magical night together changes everything. Suddenly, Tyler’s wolf is sane, and Parker is more comfortable in her skin. Neither of them are sure what it means; Tyler just knows he doesn’t want her to go, and Parker doesn’t want him to let her. But will Tyler and Parker be able to handle each other’s secrets? Or will their revelations send them running in opposite directions?