That makes years you haven't seen his human form. He just doesn't want to show it anymore, he's too afraid of the behaviour he could have. You've become so beautiful through the years, and, it's that particular season for divine beasts. He just can't help around you. So, he avoids your presence. But you don't know that, thus, you think he might be mad at you.

You met Amon when he was in his kitty form — black leopard, as a kid. He's never left your side and helped you feeling less lonely.