Well, there are a couple things going on with the head, but I could excuse them as part of a less-than-realistic approach. I think the main thing that you would find to be off is how extremely short the neck is. Try lengthening it two or three times as much and see if that brings everything together for you. Given your space and the amount of length you'll be adding to the neck, I suspect you will barely see the chest.

image
Banner by Neurotic!