1994 Mercury Villager only fuel pump and headlights work

I've had this '94 Villager with 285000 miles since it was brand new. I was recently driving it when the ABS lights came on, the dash lights started dimming and brightening randomly, and I heard a relay clicking noise. I pulled over at the next intersection and shut it off to reset the computer hoping something sent the computer into panic mode. When I tried to start it again, I got nothing at all other than the fuel pump whine. The headlights work (bright and dim) as well as the fuel pump, but nothing else works. No dome lights, park lights, clock, brake lights, starter, wipers, nothing. About 30 minutes after I stopped, I got it to start up again as usual, but as soon as I got a couple feet, it did it again and I haven't been able to start it since. I checked the ground to the block and frame and they turn out fine.