Her Broken Bear by Summer Donnelly

Answering an emergency call from her best friend, twenty-eight-year-old Hadley Mills runs to Maxwell Mountains, North Carolina. There she meets Hunter, explosives expert and bear shifter. Hadley is able to heal Hunter’s body, but his heart and mind are beyond her control.
Thirty-year-old Hunter Bromstad has a broken bear. Sent back from a battle with more internal scars than a man should carry, Hunter can’t control his bear. But when he falls in love with a nurse practitioner, his life is turned upside down. Can he learn to control his bear? What about the years of service he still owes the government?

And when a fire breaks out on Maxwell Mountain, will he and Hadley be able to survive the fallout?