IWTL how to stop ending up alone at social gatherings

This happens whenever my wife and I go out with her family. They're good people and I don't have any issues with them. But they are a big, loud family that love have a good time.

For some reason in these large gatherings like wedding or birthday parties, I just freeze. My muscles go tense, I start getting anxious and all I stick one spot. My wife loves to float around these parties so I often end up alone at everything.

I want to learn how to stop being so anxious and just have fun. I'm tired of being worried about how I look dancing with my wife or not knowing how to jump into other people's conversations. Me wife does it flawlessly and I want her to stop worrying about me when we go out.