Relax a bit. Much less than we probably imagine is really under our control. Note this quote, for instance, from two psychologists recently summarizing at Slate some findings on genes vs. environment: “Genes influence not only our abilities, but the environments we create for ourselves and the activities we prefer—a phenomenon known as gene-environment correlation. For example, yet another recent twin study (and the Karolinska Institute study) found that there was a genetic influence on practicing music. Pushing someone into a career for which he or she is genetically unsuited will likely not work.”
In other words, genetic factors significantly influence not only the degree of talent we’re likely to display in a particular discipline (music, math, literature, etc.), but the temperamental energy and patience that we’re likely to bring to it in the first place.
So chill out. Less guilt seems to be in order if you’re a parent, or if you’re berating yourself for not rising to what you believe is your potential. It’s okay that you’re temperamentally anxious, or not a scientist or screenwriter. It’s not your fault. You did your best. Let it go.
I like this (I think I recall it from one of Jack Kornfield’s books): “I’m not okay, you’re not okay, and that’s okay.”
Prometheus Unbound 
Yeah, it’s fine to say all that till you find yourself an introvert… then nobody thinks you’re okay.
I’m an introvert, and I think you’re okay. : )
Parents have zero influence of how their children turn out. All manner of research indicates this (plenty of it from Karolinska). For laymen, the most compelling example would be that adoptive siblings, who grow up together but are biologically unrelated, are no more alike than two random strangers. Even plenty of high IQ people refuse to believe it – and of course they refuse to look at the evidence as well.