Okay, for some actual advice.
Just tell him and get it out of your system. He might be "insane", but that doesn't mean he doesn't have a heart. Just tell him you were using the fishing rod and it snapped in half spontaneously. Tell him it was an accident, and you're deeply sorry. Most likely, he'll tell your parents and demand money for it. Worst-case-scenario, you get grounded for a month.
I've been labeled as weird, insane, and crazy. I am none of those, yet I act the way I do because it entertains me, and others around me.
"Oop, sorry, asshole, you had the wrong religion, enjoy hell. Buh-Bye."