If you're like me, and +watch a ton of professionals, you'll probably have a few of these moments in your dA lifetime.
You'll have a moment of pride and awe at your creation, only to log in and within seconds get a reality check on your actual skill level relative to others.
It's a knee-jerk and natural reaction; you see someone creating something, just like you, but doing it with a much higher level of skill and execution. I've learned that, in the end, it's not about comparing yourself to other artists, but rather aiming to be the best at what you do and never stop trying to improve.
Everyone starts somewhere. Use your superiors for inspiration and motivation rather than let them kill your confidence!