It would start but run very rough and stall quickly?

I have a 2002 Dodge Ram 1500 4x4 QC Sport. Just the other day the Truck stop running. I had a 1/2 tank of gas in the Truck when I stopped at a store. When I got back to the truck and tried starting it, it would turn over but not start, unless I press on the gas peddle then it would start but run very rough and die quickly, like it was out of gas. I then noticed the fuel gauge was reading empty, which I thought was very odd since I had a 1/2 tank when I pulled into the store. I was lucky enough to be close to a gas station and was able to put a full tank of gas into the truck and still the gas gauage did not move from empty. When the key was left in the on postion I noticed a clicking sound coming from the fuse box under the hood and the fuel pump was making a cycling sound. Thanks for any help and ideas.