Anything But Typical by Nora Raleigh Baskin

Jason Blake is an autistic 12-year-old living in a neurotypical world.Most days it's just a matter of time before something goes wrong. But Jason finds a glimmer of understanding when he comes across PhoenixBird, who posts stories to the same online site as he does. 

Jason can be himself when he writes and he thinks that PhoneixBird - her name is Rebecca - could be his first real friend. But as desperate as Jason is to met her, he's terrified that if they do meet, Rebecca wil only see his autism and not who Jason really is. By acclaimed writer Nora Raleigh Baskin, this is the breathtaking depiction of an autistic boy's struggles-and a story for anyone who has ever worried about fitting in.