Grand Am cranks but won't start

dwill1

I will try to do my best to detail every thing that happened so I can get the best answer.

I have a 2000 Pontiac Grand Am GT with approx. 150,000 miles on it. I was driving down the highway with the cruise control activated, cruising at around 77-78mph when all of a sudden my RPM began to drop and naturally my speed went as well. The more I accelerated the quicker both dropped until the car cut out and I had to coast to the shoulder.

I tried to start the car and it would crank but not turn over. The lights would go dim as I did this but go bright after I stopped cranking it. I waited for a little while and tried again and it turned over but immediately shut off. I did this until the battery died. Got a jump an hour later and it did the same thing. 

Besides the above listed diagnosis, could there be anything else. Also, I couldn't hear the fuel pump click on but it was also pretty loud on the freeway.