I think its ya age..or a stage in your development to be a man...It happened to me at your age and as-well people staring...But...they are not doing anything at you in particular i soon realised...I reckon it is a positive good trait of your character to acknowledge this,it means you are conscience of the people,actions,mood ect around you,you are not so mixed up in yourself like most and can sense these actions from others...It is good once you over come this fear that it is personal.I think that some people are so insecure they have to belittle others or take the pi$$ out of them...make jokes.....stare for a reaction that suits their pathetic view of them selves .
Or you could be a paranoid schizophrenic?..But i am no expert.
You might be feeling a bit insecure. Or passed bullying situations are making you think so. I seem to do that sometimes too, mainly because I'm self counscious about certain things...
idk but i got the same problem lols but then most of the time i do act like a dork...
Your just A.) Really self concious. or B.) Very paranoid.
Maybe your feeling self conscious about yourself?
Maybe self-esteem issues