Tarnished Knight by Bec McMaster

After a vampire attack left him struggling to leash the dark urges of the craving virus, John ‘Rip’ Doolan, thinks he’s finally starting to master the darkness within. The only thing that threatens to shatter his control is Esme, his closest friend and the only woman he’s ever wanted. If the stubborn beauty ever realized precisely what was going through his mind, their friendship would be ruined.