Why is this so painful?

I sincerely wish I was better at digital painting (or whatever you prefer to call it). I find it very frustrating. When Shaun Mooney came in to talk to us, I found it quite enlightening and his work really impressive - especially when you consider how fast he does these drawings.

So, I have tried to incorporate some of his techniques and things he talked about in to the work I'm doing at the moment - I've tried blocking out shapes and building on them, flipping the canvas while I work and trying to 'imply' things with brush strokes rather than finely draw it. Well, that's what I'm trying to do! I've started on my GasMask man and I thought I'd share what I've done so far - which I'm actually quite pleased with. Feedback would be appreciated, but please be gentle!