Catalytic converter broken, Help?

I have a 2003 Honda Civic. I believe my catalytic converter has broken up inside since every now and then I hear rattles and the engine light came on. I was trying to see what my options were. I know it is not a part that the car needs to run however I don't want my engine to get damaged due to clogged up exhaust. But it is a pretty expensive part. I just need advice on wether I should clean it out with cleaner and chill or would that be a waste of time and I should just replace it?

P.S. I am a broke college student, I'm trying to see whatever is more cost effective. But if you guys think it should be replaced I understand. Which begs the question I've seen some aftermarket cheap cats, are they worth it?

Sorry for the long story and a big thank you to whomever chooses to answer this.

Read more: Catalytic converter broken, Help?