I was actually surprised to find that the word fetches so many results in a Google search, mainly because I've never heard or read it used, and it had only just occurred to me. I guess I didn't coin it after all. Of course I knew there was a good chance somebody else had already thought of it, which is why I went agoogling, but I didn't expect that so many other people would have thought of it.
The neologism testeria is a companion to the word hysteria, which is derived from the Greek word for womb. Testeria, of course, is derived from testes. After all, why have only one sexist word when you can have two? True, we do already have dickishness, but I don't see that as the equivalent of hysteria because it doesn't imply any sort of derangement. Being a dick is just an attitude issue. Being testerical implies being a bit crazy and losing control.
Anyway, now that I know the ball (or testis) is already rolling, I intend to start dropping testeria and testerical into conversations. It will be useful when discussing soccer, ice hockey, politics, and talk radio. With any luck, the word will take root, and even start being misused in the same way hysteria is. Maybe guys will even stop saying that movies like Animal House are hysterical and start saying that they are testerical. It's mostly guys who laugh at that stuff anyway.