Horrible smell comes from my noses.why?

Added 3+ months ago:

i'm embarrased as i always keep certain distance when talking to anyone.i heard many times people talking about that ,and now,noone wants to live with me.Sometimes ,i cried a lot in my room as i don't understand at all what in going on in my life.i've been souffring from this for almost 4 years now and everytime i go to the doctor ,they say they don't see any problem..when i sneeze ,i can smell it