Being nervous is never truly a bad thing. True, there are times when we feel as though our nerves are playing mental warfare with our bodies about giving a presentation or going in front of a panel of professionals. however, being nervous means you are there, in the place you need to be at the right moment. It's not going to turn out fabulous all of the time but, there is a difference from being scared and being nervous.
It just takes practice and time to remember to calm down.
Just like I have to remember to do the same with meeting professionals in the real world of design and advertising. It's just people who don't know you yet.