The Wrong Bride by Gena Showalter

Vacationing in Scotland, schoolteacher Elizabeth “Elle” Darcy anticipates picturesque landscapes, castles of old and kilt-wearing charmers, not awakening in someone else’s body. Worse, that someone just married enigmatic billionaire Callen Bruce. Though that’s not the biggest problem. To the rest of the world, her new “husband” runs an elite empire. But behind his public persona, he’s a king of berserkers locked in an ancient, supernatural war with wolf-shifters.
Determined to reclaim her normal life, Elle will do anything necessary to switch back with Callen’s real wife. First, she must ditch the disciplined warrior. An impossibility when he refuses to relinquish the bride chosen for him by fate, even though he despises her. Or does he? The growing heat in his eyes says otherwise. Not that it matters. There’s no way this temporary queen will fall for the moody, broody secretive warrior who belongs to another woman. Nope. Not Elle. Not ever. Probably.