Well congrats on finding out WHAT is wrong.  Now you know the sound it makes
when the belt breaks!  lol

You might want to take it to a shop that deals with either VWs or Audis.

OR of course can be done by you if you are up to a little challenge AND a
good learning experience.  Not sure if I have ever done a timing belt for a
5 cylinder engine in a 4000 body even though I owned a coupe/GT.  There
should be enough room to do it easily though.  The hardest part is
reinstalling the lower crankshaft pulley bolt tight enough so it does not
come off in a few months.  You will have to lock down the
flywheel/driveplate and then you can torque down that bolt.  I use a brake
spoon to lock the flywheel down through the upper access hole.  Works quite
well too!  :-)
To loosen that bolt you can use the tool or with a long flex bar and socket
the starter will provide enough torque to loosen up that bolt.  Be careful
with this procedure though.  ;-)

MAYBE your crank pulley will have four bolts on it that will allow it to
come off of the crank sprocket.  THEN you don't have to deal with the bolt.
8^)

IIRC you will need:
timing belt
water pump (it adjusts the timing belt)
idler bearing
seals (if you are replacing them)
V-Belts (if they need replacing)
coolant