94 Altima HELP!!

I stopped to get gas. Turn the car back on and the brake light and battery light are on and stay on. After about 3 minutes, I noticed my horn did not work. Then, while still driving, the a/c started to die along with the lights in that area. When I turned my headlights on, the speedometer stopped working. I tried to accelerate and it wouldn't. I had to get off the gas, and then do it slowly. Now the car will not start. What is wrong with it??

Check your belt tensioner. Also, maybe the alternator.