jeeze, I relate to whatever it is you described 110%. I don't know how old you are, but I'm 29 and kind of used to all you mentioned. I became aware of it around my twenties or even earlier. I believe certain people -and even certain (herd) animals- have a heightened awareness, that serves a purpose (imho). It's a bit confusing cause it resembles social anxiety and it deviates from the social norm.
On life being pointless : i'm in it for the occasional extasy, and only then and there, I know it's all worth it.
I dated an LCSW for three years and she thought that I may have social anxiety, so as a test to prove my commitment to her I saw a shrink. They prescribed me different drugs to dull my "anxiety." The drugs did nothing for me. I mean I could have just been taking sugar pills. I'm certain what the deal is is that I typically ignore engaging with people because I hate feeling too much. You know the deal, often talking face to face with people reveals some kind of heavy sadness or bizarre awkwardness about them--probably a result of how fucked up our ideals are these days. Of course this not always the case, and I have much more tolerance with people I've know for years.
It's refreshing to think that this is some heightened sense of awareness, but I'd gladly take some opiate to eliminate it any day. Could you talk more about how this sense helps serve a purpose in the world today?