Sweet-blood, by National Book Award winner, Pete Hautman.
Lucy Szabo is a barely-controlled diabetic, so understandably, she spends a lot of time thinking about blood. However, her studies online take her down virtual alleys and into Vampiric chatrooms where others with a less wholesome approach discuss their bloody fascinations. There, she meets Draco, who actually claims to be a vampire. The thing is, she’s, “not 100 percent sure he’s kidding. You meet a lot of weirdos on the net.”