I've always been an introverted person, and I'm fine with that. I enjoy solitude and reading books over going out and partying with people. I have social anxiety (pretty badly) and OCD behaviors that are becoming more frequent. Anyways, I just like being by myself and thinking about things but at school people are always wanting to constantly talk to me and asking me to go out to do stuff (like friends want me to go to the movies and things like that) and I don't want to sound rude to them by saying for them to leave me alone (also, 2 of my classes require partners a lot so I have to be nice to my partner so I'll, you know, HAVE a partner).

It's just annoying to have to act all extroverted around people just so they don't ask me "why you look so depressed", though i'm just thinking or reading (God forbid i'm not constantly texting or watching trashy t.v. shows on my iPhone).

How can I gradually make people realize that i prefer to be alone without being rude?