I don't think social anxiety is real.
These categories were made up by psychologists, to try to better understand the mind. Just like the zodiac was made up by whoever made it up, to try to understand peoples' minds and how they work (as well as other things). Some people subscribe to the zodiac. They really feel as though they exhibit the characteristics of their sign, and they even have whole forums talking about the zodiac. Just like SA people. (Obviously, the zodiac is trying to understand a fictional universe, whereas psychology is trying to understand reality.)
But the mind is not as categorized as the DSM-IV-TR. The very fact that a disorder is not considered a disorder unless it effects your quality of life. Anyway, I think that thinking that you have Social Anxiety Disorder, that it's a glitch in your brain, that nobody else has it or can understand it, contributes to your experience of SAD.
Accept that everyone has these feelings, even though you might not know it. Treat yourself like a normal person, and realize that you are worth being respected. It all comes down to: Just do it. Ignore your social anxiety, and it will stop bothering you. It worked for me, to a point.
Of course, talking about things with like-minded people is also beneficial. Which is why it's nice to have these made-up psychological categories. (I do like psychology, and think it's useful, it's just not an exact science.) It's nice to have this forum, and it's nice to vent. It's a huge boost to know that there are people out in the world that have the same problems.
But really, it's not as if your mother checked a box when you were born "() Give me a baby with Social Anxiety Disorder SAD" It's only as real as you make it.