Do Nervous Habits Like Bouncing A Leg Occur With Social Anxiety Disorder?

I’m a sixteen year old junior in high school. I’ve been diagnosed with depression, anxiety dissorder, IBS (Irritable Bowel Syndrome), and various other nervous habits. I’ve been looking into my joints tendancy to snap, crackle, and pop at odd moments even when I’ve been moving around a lot as well as my excesive tiredness after coming home from school. I don’t do any sports or straining activities. I do tend to read a lot though and spend no more than five minutes in one position when sitting or laying down with my books. So, from that I am guessing that my joints “sounds” aren’t being caused by lack of movement as I never stay still. So, I thought they might be caused by tense muscles so I looked that up and found that tense muscles can be caused by repressed emotions, social anxiety, stress, and the like. I know already that I suffer from most of the causes of tense muscles, but I wanted to know if I suffered from a mild form of SAD as most of the descriptors fit me. I’m quite socially inept around people my own age, my nervous habits go into overdrive when I’m not in my own head or reading whilst in public, I litteraly can’t speak publicly (I’m in a Speech and Debate class and when I go up to present I always burst into a hysterical fit of laughter and cannot stop), I spend the majority of my time reading to the point of being unable to tear myself from the book until I fall asleep, and various other parts of it. However, many of them have seemed to manifest mildly in me. Maybe it’s just introversion, but I’d rather not self-diagnose even though I probably already have.  

-Cassandra