Gaggery
Gaggery is when you're so into something you'll probably die from it. You'll probably ignore everyone else and just talk about it nonstop.
She got a new outfit and now she's talking about it like it's her last breath. She's a gaggery.
He got a new song and now he's singing it in the shower every day. He’s a gaggery.
This kid got a new toy and now he's ignoring his homework. He's a gaggery.