1998 Saturn Station Wagon car won't start

the car started and ran for a few seconds then died, after this there was nothing, no power, when I turn the key the clock on the radio gos out then comes back on when the key is turned off. I have checked all the fuses (in the car and under the hood)all seem to be good. The battery is good. I changed the ignition switch but accidently turned emergency flashers on and killed the battery. Once the battery was charged I tried starting it again and again it started and ran a second or tws and died, now there is nothing again.