Whats... wrong with me...?

Okay, If I see people talking in the hallways of my shcool, or anywhere else... I cant seem to shake the felling that they are talking about me in a negative way. I my best friends were to talk to someone and do so much as look at me while they were talking I would automatically think "What are thay saying! Does he hate me? Does he only hang around me to pretend that we're friends? Does he just talk negatively about me when I'm not around!?" ... but this sort of thing happens whenever any I'm in situation where I'm not engaged in a conversation with someone, but they look at me. All I want to know is... What is this problem called... Thats all I need to know.