Jeep Grand Cherokee Stuck in Park

the other day i parked my 2008 jeep grand cherokee, ran into the store, came back out, started the vehicle and it would not shift out of park. i looked in the manual and found how to reset the shifter by removing the small plastic rectangle with a flat head screw driver. i was able to drive the jeep to the next place, but had no AC, windows, radio, signals lights, etc. When I stopped at the next place, turned off the jeep, and then turned it back on, everything worked fine.
Then 3 days later it happened again, and now nothing electrical works, except the odometer reading and stuff right in front of the steering wheel.