It looks like you have a good grasp of shape and lighting, which is good. Your anatomy looks a bit wonky though. Even though you may want it to look disfigured/dismembered, I strongly suggest that you take reference pictures of yourself or someone else in that position.
Do some quick sketch studies of arms, hands, and the shoulder area before coming back to this piece. Some things should "click" when you come back to this.
Also, that's a wonderful pumpkin. I would accentuate the light that comes out of it so it can pop a little bit more.