I think you need to put aside the digital paintings for now, grab a box of pencils and a stack of paper, and study form, anatomy, perspective, light, and color. Study every day, and you'll be amazed by how much you improve.
"Trying is the first step towards failure." -Homer Simpson "Sucking at something is the first step towards being sorta good at something." -Jake the Dog
If you fail at something, you suck at it, so trying is therefore the first step towards being sorta good at something!