We have 2 cats, one older female who's mostly well behaved, and a
younger cat (3 years old now).

The youngest cat was always hiding, from the time he was a kitten, he'd
hide and was/is very skittish.  This seems to be getting worse with
age.

He's afraid of our ceiling fan, avoiding it like it's going to detach
and chase after him.  Even after a year, he seems to never get used to
it.  He's also very antisocial, running when the doorbell rings or
company comes over.

Earlier this year we discovered he stopped using the litter box, using
the corner of an upstairs bedroom instead.  He's ruined the flooring
and cost us alot of money for repairs.  So, we closed off this room and
focused on the litter box, trying varous locations.  He found a new
area to use in the corner of a downstairs livingroom.  We tried Comfort
Zone with Feliway Plug-In for Cats and it seemed to have no real
affect.  We then purchased a cabinet litter box, with 2 levels so he'd
have more privacy and the litter would be easier to maintain.  This was
hell to get him to just go inside of it, but we eventually got him to
use this half the time.  I've now taken to rearranging the furniture to
try to focus him on the litter box and away from other parts of the
house.  We love our kitty, but I think my wife is losing patience with
him.  We've had him since he was a few months old and he's always been
in a loving household.

Has anyone tried prozac with their cat?  Our vet suggested this the
last time we spoke to him.  Giving drugs to a pet is not my idea of the
right thing to do, but we're running out of options.

Can anyone help save our house and our kitty?