I have had this goofy quirk since I was young, and I wonder whether it might be a symptom of social anxiety/OCD/something else. Any advice/suggestions/etc. are very much appreciated

:
I have been feeling a little down lately (not in general with my life, just a little blue for some reason)....anywho. I apparently sit at the "quiet table" in my class, and I'm probably considered the ring leader of the "quiet people" in there. Mrs. X decided to call the table that two other girls and myself sit at the "quiet table" in class today and, as a result of my delayed reaction to the comment, I am now a bit upset (she also said something to the effect that she wants us to talk more in a really nice way). First of all, I'm not all that quiet a lot of the time. I just happen to be quiet in that class (and another class here lately) because I don't want to sound like the instructor since a lot of how she says things is the same way I would say things (like her mannerisms, how she seems to make up funny words, her philosophies, etc.)--she's almost like what I would imagine to be an older version of me, though I would be married to a great guy--like my current boyfriend--long before that time

, so I end up being really quiet...nodding and smiling here and there. I don't know why I do that, I just don't want to seem like I'm copying/mimicking someone. I also want to be seen like everyone else...most of the time, I tend to sound more like a teacher (studied to be one at one point in my life)/mom (my friends have called me their mom) in given situations than I do the "rest of the crowd." Most of the other students seem kinda juvenile and silly to me, anyway, so it's hard for me to fit in with them. They even ran up stairs, in a pack, today to see who Mrs. X was treating (when someone fell down the stairs at school during the class

, and Mrs. X went dashing out of the room to see the person), as I just sat outside the class, waiting. I don't want to have this annoying behavior follow me around for the rest of my life. In most situations, I'm myself, but in situations where the person who I feel that I'm similar to is near me, I tend to clam up. An example would be when I'm around my aunt (who I'm supposed to be a repleca of when she was younger--who, incidentally, also reminds me of this instructor

), and I get really quiet/behave in ways that I can avoid having to talk to anyone while I'm around her

. This behavior has been plaguing me since I was a little person, and I just want to knock it off and be myself. YEESH!!! Any suggestions? Are there books I might read? Online research? I love to read anything and everything on any topic under the sun

. I have become adept at talking myself into positive/effective behaviors when little nuisances like this occur, but I just can't seem to talk myself out of this one as well...
Additional Info: I have always been considered/ considered myself to be reserved, though I have broken out of my shell quite a bit since I was younger.
Thanks For Your Help,
Colleen