Wow, someone else with a mom from hell (well, mine wasn't that bad but she has a ridiculously pessimistic outlook on... well, everything. So, yeah, according to her, I was a screw up my entire life, though I've proven her wrong time and time again. Oh well...)
In any case, your grades never ever define you. In the end, there is only one question: Did you do everything you could do? If yes, then anything else won't matter. You fail? No biggie, dust yourself off and try again. Grades not as good as you hoped it would be? No biggie, kick yourself in the butt and work harder from now on. You passed everything with flying colours? Nice but not as big a deal as you think it is. Keep it up.
This exam (and pretty much all exams) are nothing but stepping stones. You stumble, you pick yourself up. It's that simple.
besides... isn't it a bit late for any nerve-wracking? I mean, you already took the exam. Not like worrying your butt off is going to change anything. Better enjoy the next few days because whatever the results are, after that there's work ahead.