Reverie - by Ryan La Sala

"All Kane Montgomery knows for certain is that the police found him half-dead in the river. He can’t remember how he got there, what happened after, and why his life seems so different now. And he has no idea why three classmates he barely knows are claiming to be his friends.
As Kane pieces together clues, reality starts to rapidly come undone, turning the real world into dreamlike alternative worlds called reveries. Kane must join his new supposed friends to try to keep the reveries in check, especially when they realize that a sinister force is drawing power from them. They will have to do everything they can to stop her before she unravels the world as they know it."