The pics are very large. Might I suggest around 900x600 or so.
The first step - especially for young people with energy and drive and talent, but not money - the first step to controlling your world is to control your culture. To model and demonstrate the kind of world you demand to live in. To write the books. Make the music. Shoot the films. Paint the art.
Nice work so far. I wish I had started out with anatomy studies when I started taking drawing seriously.
One thing that I would suggest is to make your lines less chicken-scratchy and sketchy. What I mean is, try and use only one line to define your curves, rather than hundreds of short lines. Your lines will become much more confident. You can still draw multiple lines on top of each other, just try and make each line you draw the exact length of the shape you're trying to define.