2002 Ford Windstar Battery, Alternator, Instrument Panel

I started out with a slow battery drain, dealer told me the battery and alternator were both good. Took a long road trip home thinking the alternator would keep the battery charged fine. A few hours into the trip the battery began to drain, I had to keep the rpm's up to keep charged (in hind site, I think a previuos jump start may have damaged the alternator). Then about an hour later, the van would only drive when the gas pedal was pressed down a certain distance (too far down it would sputter out too light and it would die down) could only drive about 45 to 60mph at this rate. Another hour later all the dash lights went on and off. Then the gauges started flipping out all over then went dead. Then the car died and would only drive for a couple minutes after each jump. Now, even when jumped nothing electrical works (windows, locks, lights, head lights, ect). Any suggestions as to what this could have been. Sorry for the long message, I'm just trying to give a good history of the problem. Thank you.