The Gathering question

I’ve forgotten the book but it’s about a small town and kids are being sucked into a shadow dimension where they are stalked by (I think) an old man(or lady) and their henchmen. At some point, the main character has sacrifice himself so his two friends can escape. Then he has to chose whether he wants to lose his eyes, ears, or mouth. Please. I need help 😭 it was written before 2015