Upcoming holidays

My son will be 7 months on the 14th. Ever since he was a newborn and still now if he is around people he doesn’t know he screams and cries hysterically and his bottom lip quivers. He also hides his face and will scream if someone looks at him. I just took him to a family get together with 5 people and he did it the whole time we were there, from 3-9. I’m getting worried about Thanksgiving and Christmas as there will be a lot of people he has never been around. How do I deal with this? It almost makes me not want to go because he gets so upset he won’t eat sometimes but I know we will end up going because I need him to get used to it and it’s tradition. Is anyone else’s babies like this? What can I do to help? It also seems to be certain people because he’s met many of my friends and been fine and certain family members.