happens to me.
when i lock the door i have to check it at least 5-10 times.
before i sleep i have to check many times that my handphone is next
to my bed. i also spend a lot of time arranging the speakers so
they are evenly spaced but they never seem to be. and i suffer most
of the symptoms you mentioned 
. it doesnt affect my
life drastically... though it becomes a pain when i'm doing art
since i'll am obsessed with positioning my lines.
glad to hear someone who shares this 'problem'.
oh dear, yr situation seems worse.....hope u get better
..
btw, another thing i read from the wikipedia article that
applies to me 100%:
Symptoms:Often,
the brain challenges the person to a challenge that you feel you
will die if you do not do it correctly.
i often give myself silly challenges, exp:if i dun finish doing
something before the phone rings i will die or if my
colleague starts talking before i do i will die etc etc
