Another problem which leaves many people feeling panic-stricken is the Christmas get togethers and meeting new family members. Again, don't worry! Some of them might be just as nervous about meeting you but if that doesn't help the nerves talk to your partner prior to the event to ask about who will be there and how they are related so you will feel like you know them slightly before the big meeting.
Try not to attach yourself to your boy/girlfriends side, interact and get to know the family. Also, to avoid disappointing each other or your families decide well in advance which family you will spend Christmas with and which family you will spend New Year with. Or even if you will spend the day together at all.