2003 pontiac sunfire won't start.

A couple days ago my battery light came on. I got my battery tested, and it
was in perfect condition. The next day, while I was driving the radio lost
power and within a couple minutes my engine lost power and would not go
over 55 mph and was revving at almost 5000 rpm's. It stopped once I
slowed down but later that day it happened again, and all electrical systems
failed while driving. I was able to get it to my house before it completely
died. It will no longer start, but all of the lights come on fine. I replaced the
alternator and still won't start, I just hear the clicking noise like it is trying to
kick over but it never does. The battery light coming on is when it started so  
could it be the starter or wiring?