I don't think textures are going to work on something this small. Look at the basic shapes you're trying to render. Such as: how much hair is on the right side vs. the left side and how it compares to to size of the visible part of the face. Proportion is key.
Also the smaller the pixel art is, the more it benefits higher contrast. Your tones are way to close to each other. Looks kind of washed out and 2D.