Don't forget to consider the possible involvement of heavy meal toxicity.
There are plenty of reports from people in detox groups who became more introverted as they became sick and less introverted as they healed during detox.
The middle aged woman who posted this hair test and symptom list once reported in a detox group that she had received the "social butterfly" award when she graduated high school. However as she became sick her personality changed. http://www.livingnetwork.co.za/files/hairtest_275.pdf
I certainly noticed a much improved comfort in social situations during my years of Cutler protocol detox. I don't know how much of the improvements were due to directly to detox and how much of it was due to the supplements that people using Cutler protocol tend to take.
A combination of supplements may take the edge off of social anxiety--low dose lithium, magnesium, adrenal cortex support, GABA, multi B.