I think if you copied the area from the shaped end of the nose to the bottom of lips... then paste that into an upper layer ... them move it downwards a bit, that would make the chin shorter and balance the features out. he would have a slightly longer nose. Then you use a blender or soft edged eraser to remove the excess off the pasted bit.
You could make some single layered copies of the whole thing and practice doing that. I can show you an end result that I make if you like...
By the way, I'm forever altering the faces that I draw, but occasionally get it right the first time. I always flip the picture horizontally to find my mistakes and I've learned to do that very early in the piece now, so that I can straighten crooked eyes etc before I finish the picture. :)