Oh, dear...before doing anything rash (throwing your dead baby into a river, off of an overpass, funeral pyre, etc.) find someone (or a friendly shop) with the campy tap and die set and give it a try. I've taken bottom brackets from british to italian, but I've never tried an italian to italian rethread.

Also, if you want to keep riding it for a little while (20k miles with the right equiptment) you can always get a quality sealed bb and red loctite/jb weld it into the shell. It'll be your last bb in there (and I wouldn't put anything like a phil in there) but most people never even overhaul their bb's.