Remember that whatever you think about yourself is true. A self fulfilling prophecy is a powerful thing. If you think you're past the point of pursuing your dreams of becoming a concept artist, the only one enforcing that point is yourself. These are some wonderfully expressive drawings and I like that with several of them you can get a sense of where the character is looking regardless of face detail or guidelines drawn in. I'd like to second the opinion of creating an armature of sorts within the figure. I believe it's important to have a solid foundation of what's happening within the body. Sometimes I do longer studies with a single drawing, doing the figure drawing, doing a new layer for muscles, and a new layer for the skeleton to really understand how the body is moving. I think you have a good sense of proportion even with your 30 second drawings. Keep up the great work and don't give up on your dreams. The future is what you make of it :)
