My car starts fine but won't accelerate for more than a few seconds. is it my engine?

i have a 1983 dodge colt which runs fine and dandy but then a couple days ago i drove it and it was running fine but all of a sudden stopped accelerating, and died. i keep trying it and trying it and it starts up perfectly great and quick but after accelerating a bit it just dies. i just want to know if this is an engine problem or like a head gasket problem or what?