The drawing is done well you have everything in the right place, good job on that! The biggest problem I see here is exactly what I tend to do all the time which is go into details before establishing the big light and dark shapes. I did a quick overlay on top of your drawing to establish the shadow shapes away from highlights on the forehead. I don’t know if this really will help but I feel that establishing these basic shadow and light areas allows the form of your head to read a bit better. let me know if that is helpful. And keep drawing!