Hello,
Social anxiety is often a part of autism, but autism tends to be more complex and as everyone has mentioned it is different everyone. I am less socially anxious than you, for example. For myself I need more time to construct my thoughts and answers in social situations, hate phones, prefer written communication as I can say what I mean more clearly. I am actually a bit of a slow responder on internet messengers and tend to write a lot. I tend to not like being touched by strangers and my comfort with physical affection is related to how well I know/like the person. I tend to avoid eye contact but try to focus on something close to the person's face so that they do not notice as much. I have been practicing being normal since I was a child so some things are not there or as obvious anymore. I am hypersensitive to light and sound, and do not taste normally. I have odd habits (eat dry pasta, tip toe around the house) but those are harder to notice. You may not do the hand flapping or related repetitive behaviours, I don't. If you are the type to be self aware and have insight than it is easier to tell how you relate to any particular disorder but if you do not have much insight into yourself than it will take more time and effort. The fact that you keep reading about the disorder seems related to obsessions, which is a particular aspie trait. I also get more upset for longer periods of time than others for little things. I am trying DBT for that, which is helpful. It is a bit odd though that you did not show many of the signs in your childhood. Some doctors will also do background research with your parents. You could ask them about your childhood and compare to what you are reading. It is good to make sure, but having a diagnosis can at least gear you towards the right programs (which are slim for adults with ASD in most countries). They might also help you find a job that will tailor work closer to your needs or (strongly) encourage a current employer to let you work at home if you are more comfortable and productive.