So maybe this is your first time going to a big party after figuring out you need to be gluten free, and you're not sure what to eat when you get there...
First, take a deep breath. It will be ok. This is easier than you think, and it will get easier over time.
Talk to your host/hostess when you receive the invitation. Explain your situation. And no, you are not a freak - this situation is more and more common every day. Offer to help in any way you can so they won't feel put upon or put out.
If you are asked to bring a dish to pass, you can bring gluten free breadsticks and SPH Pizza Dip. Or offer to bring a vegie or fruit tray and your own dip(s). I'm sure the dieters in the group would be glad to have a healthier option as well.
Do your homework before you go - find out what commercially-available brands (and that's food as well as drink) are safe or not. If you're really not sure, don't eat it. If you're worried that your dish is all you'll be able to eat, have a safe snack before you go.
If you should accidentally get "glutened", you'll probably know pretty quickly. If you feel ill, try to excuse yourself graciously and gracefully. If you need to call in sick to work on Monday, do it. Take care of you so you can be healthy. Have simple meals for the next few days, and stick with food that's really easy to digest, like a vegie soup made with GF chicken broth. Yogurt smoothies. Green juices. You get the picture.
Hang in there - like I said, this does get easier over time. By the next big bash, this will have become a habit!