Its hard to tell from the angle but you are pinching with your knee and it looks like you are holding on with your whole arm...I can't tell a whole lot but it looks like you need to get more out of the saddle too...
Second Picture(front view):
All you need to do is pull your toes in (its hard to break this habbit, I do it too!!!!)
Third Picture(Side view):
Put your weight in your heels, and that will push your body out of the saddle. You also need to bring your leg foward just a little(right behind the girth) and that's about it!!
Overall you having impressive form for teaching yourself!!! Congrats hope to see more pictures soon!!