What is the authenticity of Chaitanya Mahaprabhu that he is God?

Hi, I'm new around here. I've been into ISKCON for ten years now (I even stayed for a while at one of their student centers in India), and it's weird that only Gaudiya Vaishnavas think of him as God – no other Hindu with access to the scriptures do. Saying he's a "hidden" avatar is a bit convenient, isn't it? He might be a great saint, but calling him God is a bit much. Some of you probably know and read a lot about him, and I haven't read the Chaitanya Charitamrita yet, so maybe you could help me out? Thanks!