1988 Chevy Celebrity Not running right

I have an 88 celebrity, it sat for a little over a year before I got it and we changed all the plugs and wires and oil and gas in it. Well i've had it for about 2 years and for the last few weeks it hasn't been running right. When I go to work in the morning it's dakr so I use my headlights and it seems to put a strain on the car my blinker goes really slow and it has a problem accelorating. This morning it was really bad when the blinker would flash on it would stay on for about 5-7 seconds then flash off. When I went to leave work it would not start all it did was click. So I jumped it off and let it run for about 10 minutes and when I got in it to go the radio was acting funny and when I pushed the brake in everything almost died so I backed out made it about 5 feet, pushed the brakes to shift gears and it died so my car is sitting at work. Please help