1995 Chevy Camaro car shut dow when I was driving

My car shut down while I was driving it down the road. Engine just quit running. The battery seems to have plenty of power but positive terminal (screw in type not post) screw is stripped and will not completely tighten. But connection is supplying power to lights and alarm. When I pulled over lights were working but I am getting no reading from my amp guage (needle not budging)and when I try to start it I get nothing car will not even turn over its like its dead. I am confused could I have lights and alarm and not have enough connection to even get a reading form amp meter. Lso have power windows and they wont go up or down. Would battery becoming disconnected cause my engine to shut down during driving down the road?