Battery, starter or alternator issues?

My car lost power a week ago today.I got a jump. I was driving to the auto zone, I started to loose power. One I arrived, Ireplaced the battery since the battery checker. Aid it was a bad battery. Car was doing well until Yesterday,
Again, my car wouldn't start. I looked at the battery the black cabl was loose. I put a nail in it until I made it to Advance Auto. I bought a terminal because the old one wouldn't tighten up. Got it replaced. I drove 25 miles and made it home just for me to loose power again. When I get a jump it turns all electrical works but it won't crank. Its turns and clicks when I try to crank it while it's connected to a battery jumper.