Whats wrong with my ball python (read description)?

The whole top of her head (shes like 7 or 8 now) is dry. Like the scales are all dry and it looks like it turned yellow. Her sheds havent been coming out good either. This has been happening since june, and when I went to the vet he said to soak her and I did and nothing really happened. So what dO i do? Shes also been burrowing in her substrate and shes never done that before in her life until a few months ago. Whats wrong? (Ill add more details if you need them, just ask)