Is this some kind of disorder?

Well, don't know how old you are. Not sure if this is a disorder but it is rather unusual to be thinking that everyone thinks of you in a ual way, especially when you talk about your mom and brothers and possibly your teachers. You really do need to discuss this with someone you trust! This is going to affect your life in a negative way if it continues. Believe me, a person who councils for a living would not think it weird as they are trained to deal with all sorts of problems! If you were physically ill you would get help, why is this different? So start with someone you really really trust. A school counselor for one. Don't go to your friends they probably wont understand but who knows.