I agree that it may be time to consult with a professional. Meanwhile here are a few resources which may be of interest:
SENG article by James T. Webb:
http://www.sengifted.org/archives/a...-conference-reflections-on-sengs-history Books and articles by James T. Webb, including
A Parent's Guide to Gifted Children (which mentions existential angst), and
Searching for Meaning: Idealism, Bright Minds, Disillusionment, and Hope (a recent work).
The book
Living with Intensity by Daniels and Piechowski.
A recent thread on perfectionism includes
this post mentioning resources for understanding mindset and perfectionism.