The Edge of Nothingness by Shayne Carmichael
Features explicit M/M sex. At the age of ten, Zach witnessed the death of his mother and the kidnapping of his sister during a vampire raid on their village. He watched as his mother's killer was murdered by another vampire, then in turn Zach was saved from a burning fire by the vampire. For years, the memory of that night, and the face of the vampire who saved him have haunted him. Talked into the insanity of a resistance backed raid on vampire territory, Zach comes face to face with the vampire he couldn't forget. Another completely new world. A world of vampires who rule and the humans they keep captive.