I was driving on the freeway this evening and all of a sudden my stock oil gauge dropped to the L (which is basically ZERO). I drove the car for probably another 10 miles because I was picking up my mom from the airport and a few other things. The car ran fine during this period. A few hours later, I started it up to drive maybe a quarter of a mile. The stock gauge was still at zero, my engine temperature was rising, and I could hear a distinct clacking sound from the roller rockers which I had never heard before. Obviously, something at this point is seriously wrong with my oiling system. I'm not even sure what questions to ask, but PLEASE help me. If my car isn't running well for the next week at least I'm basically FU-CKed. Any ideas you have about what's wrong or what can be done to fix it is most appreciated.