2004 Ford Taurus stalling out

I have a 2004 taurus with 48,000 miles. In the last week the car has been stalling out right after I turn it on. It will start and quickly rev down into the 200-100 rpm range and then stalls and shuts off. The check engine light has been on. Im sure there are also electrical problems with the car because it displays messages like "low oil pressure" "check brake system" when the brakes work fine and oil was recently added. Also the headlights and interior lights flicker when car is turned off. On a rare occassion I will be stepping on the gas but the car will start to slow down as if I had let off the gas.

any help would be appreciated