Beginner needs help making first amigurumi character please

Hello, really hoping someone can help me. I’m trying to make an amigurumi fox and having difficulties even completing the head. As far as I’m aware I’m following the pattern correctly but for some reason I can’t seem to make a complete ball. Still got loads of space at the end. The wool says to use a hook sized 3-3.5mm. Used a 3mm hook. Can anyone suggest where I might be going wrong? Perhaps I’m meant to use a slightly bigger hook?

Usually these are knit fairly tightly but it depends on the gauge given in the pattern. Can you give us a link to the pattern or a pattern name?