I didn't have social anxiety. It was that I had never had the opportunity to learn how to create value for others in typical social situations. This then compounded on itself since, in paying attention to my own experience, I wasn't paying attention to the feedback I was getting from others about what sorts of interactions they liked. E.g. looking at people's faces more. It was helpful for me to realize that for extroverts, socializing was more like a slot machine. If this pull didn't hit just go try again.
This means that introversion and extroversion are somewhat self fulfilling prophecies, as most personality factors are. Introverts are more neurotic, so they hang on to negative emotions longer. They worry about others hanging on to negative emotions longer too. If introverts hang out with other introverts this is somewhat justified. Extroverts often forget about a negative social experience as soon a they are off to the next one. So the slot machine (stateless) model is justified the more they are hanging out with other extroverts.
Extroverts are subject to stronger mimesis and thus do better in healthier cultures, so it makes sense that they pay attention more and agitate more for good cultural norms (from their perspective). Introverts outperform in unhealthy cultures via insulating themselves from that.
This is all complicated by the fact that none of this stuff is binary, but it still helps me orient myself.