Wow, that is amazing. I really feel the lonely, frustrated anger coming through the whole picture. Here are two corrections:
Shorten and thicken her neck. A good rule of thumb is that, if the character bowd their head as far as she could, then her chin would touch her wishbone.
Thicken and straighten her waist. Her lower back is too thin and curves inward too much. Also, her core should be strong like the rest of her body.
Make sure you list the source of the image give credit to the artist. Otherwise, FUCK YES i want this as a skin. I even have a mouse pad of this and this as one of my background images.