Who Am I?

Harvey is the perfect child. He has good grades, a very popular person, and is on the basketball team. The only bad thing that ever happened to him was when his family had died in a car accident and Harvey is the lone survivor. Luckily, he was adopted by his father's good friend and has had a great life. Life is now perfect for him.
Or is it? He has always had nightmares of that day, especially on the anniversary. It always shows that his family actually died a brutal death, but it's not real. That's what he always thought until the day he found his so called dead twin sister alive and says that his life is all fake.
None of this is real and if he doesn't get out soon, he'll be dead..... Who can he trust? Who is telling the truth? Who is he?