Memories and Vampyrs - Dark Journeys Series

Our protagonist named Judd meets a vampire on the beach in southern Califorinia after he is discharged from the US Navy in the 1960s, and she tells him that it is actually "VAMPYR" pronounced vam-peer. What is astounding to him and his therapist in present-day Atlanta is that she still exists and has a doppelganger or double-walker. Seda is her good half, but her evil half is Lucia who proves to be a severe threat to his close friend Stephen back in his original state of Illinois.
Among other problems for Judd is staying alive, particularly after a close friend is murdered.