2000 Saturn LS1 high Idol and no power

I hope I do this right. Car ran fine the night before. Next morning go out to start car to warm up to take my girlfriend to work and it starts but fans are on high speed with high idol. didn't want to turn car off and have it not start so I just waited for girlfriend to come out and proceeded to take her to work only being a mile at most. Once there I could smell something that was very hot girlfriend got out and I looked under car and saw catalytic converter glowing orange. Let it sit for 15 minutes or so and figured I should get it at least home. So I drove it back home same deal very hot glowing catalytic converter with smoking coming out from bottom of car. Went in house decided couldn't do anything till it cooled down anyway. Later came out took exhaust off from manifold to rear of car and separated catalytic converter from rest of exhaust. I figured it was clogged and proceeded to unclog or punch hole through catalytic converter. I did and put it all back together and started car and still had high idol and fans on high speed but no more glowing catalytic converter. Put code reader on it later that day and code P0300 was the only code to come up. I've down various test to check coil packs, new plugs, looked for vacuum leaks need help please help I'll try anything with in reason. Thanks