The Romancer by David Coddon 

The Romancer is Adam Cates, who has known the kind of obsessive, all-encompassing infatuation that beguiles the most passionate lovers, a state that psychologists call "limerence." But the feeling has flown along with the love of his life, leaving him to wonder and agonize. "Is it her I miss the most or is it the high of being in love?" Cates begins to believe that the answer lies in his personal reconciliation of love and sex. So begins a journey through the heart of hipster L.A. and at the same time a journey of self.