Continuing the on the topic of working a larger or formal event (specified as specifically networking or not)...
We walk into rooms every day and don't worry half as much as we do when someone says "networking event". Do you worry like this about weddings, concerts, parties, etc.?
Actually, I do :-) But again, I have a reason/goal (step one) for being there and I've thought through my idea of a good outcome for attending.
That's step two: before you even walk in the door, what's the best possible outcome of you showing up and what might you need to do to make that happen?
Now that doesn't guarantee you the outcome but you'll be at least a few steps closer.
Step three: remember this is one event in all the events and daily networking you'll do. You don't have to solve all your networking issues in one plastic glass of wine. You can add to the collective effort of your practice. Cut yourself some slack and put the event in perspective.
Step four: remind yourself that you don't have to be exceptional; you should be real (sincere/ approachable/ etc.).
Step five: plan your introduction. Please don't stick to the name/rank/serial number approach. Add to it. Change it. And think about it in advance. Even I forget my name in stressful situations.
You can go alone, go a with a friend or peer, go for a defined amount or go planning to be the last one standing.... just go.
With this pep talk ready, you step into the room...