2002 Passat 2.8 wont start and only hitting on one cylinder

I have a 2002 VW Passat. It has the 2.8 6 cylinder. It is also a 4motion GLX. I bought the car with 165,000 miles on it. The problem is that it has always had a miss in it, but not all the time. It was showing misfire on cylinder 2 and 4. I changed spark plugs and the coil pack. Then one morning when I started it, it ran like it wasn't running on all cylinders. So I turned it off. As the day got warmer, I started it again and it ran fine except for the occasional miss. Finally I was driving down the road and it started the missing real bad, losing power, etc. I got to my destination, turned it off and it hasnt started since. I have been told that it could be the cam shaft position sensor. I did put the NGK spark plugs in it and replaced the coil pack a couple months ago. When it is on the computer and I am trying to start it, it reads that it is only firing on 1 cylinder. Any ideas??