This is my first major holiday after being diagnosed as well, however I am approaching it with joy. I am looking forward to being able to eat without feeling sick and I think that's the most important thing to focus on. I also think that being gluten free will open the doors to a lot more 'tasty' food and experimenting if you are willing to do so. In terms of dealing with everyone else eating gluten products around you try cooking for get together's yourself or finding a dish you can eat that you absolutely love and bring that if you can't cook the entire meal. It get's difficult but cooking takes away a lot of the stress because you are doing something for yourself, you know you can eat the outcome and other people will love the food.
Be sure to also mourn the food you will miss because not doing so will have a bad impact, but don't let that loss control your life. There are tons of gluten-free alternatives to holiday favorites.
Remember, just remember how good you will feel!