95 toyota camry wont start

This morning my car wouldn't start. The inside
dash lights would come on but when I tried to turn
it over it made a loud click and everything shut off.
Long story short I cleaned my terminals changed a
burnt 7.5 fuse and has the starter tested and it
failed but even after replacing the starter it does
the same thing so I also replaced the the starter
relay but still not turning over    when I put the keys
in the ignition all the lights come on but when I try
to crank it absolutely nothing happens except my
clock radio goes dim     and I also had my battery
tested and it was good.  Could someone maybe
have a clue what's up ?  I just spent $200 dollars
and it still won't crank