1999 Dodge Dakota V6 Magnum starts but stalls right away?

I Just bought this truck about 2 months ago and i have replaced the filer neck for the gas tank, battery, and Serp belt. i was driving my truck today and was going into my neighborhood and while driving i heard a snaping noise and lost steering. i drove about a .25 mile to my destination and found out that my serpentine belt snapped i just replaced it and started the car up to seat the belt and the car turn off. i started it again and it turned off again i saw some smoke come from the engine and saw it was coming from either the fan or cam drive. this car has 80000 miles on it and was used to drive to the dump and back and i keep having problems with it.