A different background would make it easier to work on the rest of the image. If you stand further away from the wall, you should be able to avoid the shadow from the flash. Framing the picture so you don't include the ceiling will make it easier to create a suitable mask. Finally, if you can find a wall in a strong flat colour that isn't used elsewhere in the image, you may well be able to use that to create a mask that naturally follows your hair (think cinematic blue screen techniques).
Wulf
ps. Yes, these pictures are a much better size
