You are not a diagnosis. You are a professional with a unique set of skills that your peers all value, and it's time that you find that value too. Self-diagnosis and bad information has caused the IT profession to be swept with the belief of being an imposter. It's cool to say the term, and it gets used an excuse that keeps us from seeing our full potential.
Imposter Syndrome is a book to help you smash these self-diagnoses. You are not an imposter, and you should be confident in what you have to offer. Find that strength by learning to recognize what you really are, silence that inner voice of doubt, and learn a tool to help others see their value as well.