Your off to a good start. Your instructor SHOULD teach you how to layout the human face for drawing. That's not your fault.
Charcoal is a wounderfull medium to work with, you can get some great shading without putting down so many lines. You are working too hard with it.
like Riaan said:
Try not to draw individual hairs, rather draw strands. Concentrate on the shadows and remember to leave ample highlights (white paper) where the light catches your hair. Keep strong white patches in the hair even for black hair!
Practice on a sheet of paper, make a circle of charcoal, now take your finger starting at the line, and smear it inward and work it to look a ball. You'll see how to work charchoal.
Did your instructor tell you about blending sticks or kneaded eracers? Don't know what they are teaching you, but I think the person should give you some techniques to work with. That would help you a great deal.
Good luck, and most importantly, have fun with it.