I'm really worried about my brother... any advice?

I believe he's just trying to find himself. Give him credit for looking up the subjects you mentioned. Sometimes one will try teasing or kind of "putting down" those around him, as he doesn't know how to say that he really cares about them in a normal way. He probably thinks these statements are funny and does not realize the "hurt" he is imposing on you. You might try telling him that you love him and what he says hurts you and makes you feel bad and that you would never say those things to him. Hope that made sense! Good luck.