Rule number #1) Never fly someone else's aircraft that I can't replace!! An old Trainer that belongs to someone else would be about the only exception to rule#1. I have friends constantly trying to pass off their radio to me when they have a high-dollar plane in the air. I promptly tell them thanks, but NO THANKS! I just couldn't handle it if something really bad happened while I was the one holding the radio. You said it yourself, "I am feeling so sick now".
I don't want to ever experience what you felt when that plane first went in!! I'm glad for you that it turned out the way it did, it could have been much, much worse.[:@]