If it happens regularly, it could be a sign that you need to see a doctor.
It could be caused by sleep apnia (SP?) or even an anxiety disorder (panic attacks). The breathing part makes this a distinct possibility. But with that said, it is most likely that it was just a bad dream: Like when you dream that you are running a race, but your legs don't move as fast as you want them to... Or you are flying in your underware over a large gathering of super models and you are unable to come down despite their crys that they want to get close to you...
Ok. Maybe I've said too much.