how do I cope with being ineffectual at best and staggeringly incompetent at worst?
You mean: "How can I become smart enough to impress people who I think that are cool unlike what I deal with."How? Well. Be happy being alone. If you try to be happy with people you'll never go anywhere in life. It'll just be unpredictable all over the place. With yourself on the other hand, well you got your internal locus and that is what counts.
continue doing the thing until you become mildly competent