Quenched in Blood by Rachel Langella

Vampire Julian Schaden warned the Asheville Paranormal Council of an impending demonic incursion for decades. Over the past two years, he and his friends have fought hard with little help because Micah Carter, the demon hunter who should have led them, abandoned his responsibilities long before his death.
In desperation, Julian visits the Carter property and finds a miracle: Thomas Carter, heir to a long line of demon hunters. Thomas knows nothing about the supernatural world, but the prospect of a real life outside the sheltered, isolated farm calls to him, and the idea of fighting the Unholy feels right.
Thomas is too young and innocent for Julian, but opposites attract, and this is one battle Julian seems fated to lose. But a prophecy from a dying mage comes with a bleak warning: the upcoming battle will claim Thomas’s life. To keep the world safe, Julian may have to sacrifice the only love he’s ever known.