I had to jump my car off earlier that morning because it wouldn't crank up. Later on in the evening the car started powering down (shutting down) while I was getting off the expressway. When I tried to crank it up again it cranked but only for a while then cut back off. I tried jumping it off but all I heard was a clicking sound after I turned the key backwards to take it out.

Installing a new battery should solve your problems.