Demon Fall by M.J. Haag

Love isn’t blind; it’s devastating.
June had her future all planned out, and it never involved hiding in a bunker with her long-term boyfriend during what felt like the end of the world. In fact, surviving the zombie apocalypse never even entered the picture. Yet, that’s exactly what fate gave her.

A game of survival. One horror after another. But, at least, she’s not alone. At least she has Adam…until she doesn’t.
Heartbroken, June wishes she could face the apocalypse on her own, but she’s seen what’s out there. Infected that are smart enough to fake what they are and the hellhounds determined to kill every last human. If she wants to survive, she’ll need help from the dark creatures who rescued her from the bunker.

She’ll need a fey, and Tor is just the man for the job.