battery is discharged.. since it has happened while you were driving, it means that the voltage has dropped too low, probably an alternator/voltage regulator and the electronics started to die off, thus you got all of those symptoms... voltage could have dipped below or SURGED above the threshold (16 VDC is the top limit)...

test the battery under a load, hopefully the battery place will have a correct tester for that... when you are back into the car, try the cluster test #9 (i think it is 9) for the system voltage and monitor the voltage while driving...

did the battery light come on too? if so, that means that the regulator bridge is defective... while the parts are repairable on the component level, it might be easier to swap the entire alternator...

keep us posted of the symptoms and further development, so we could give you more ideas....