I had a group interview last week. My group interview was a little different. The interviewers gave the group a case study to read and consult on for 25 minutes. They did not ask us any questions but did want to see how we worked in a group. It was important for each one of us to stand out as individuals and make our points heard but be sure not to over power/over talk anyone. My program is for mental health counseling so maybe that had something to do with the way they conducted the group interview... At the end of the day the person next to you is just as nervous, if not more nervous. I would not worry about your competition because you have to focus on selling yourself. Think of it as you looked good on paper, now the department wants to meet you and get to know your personality. You will do fine. I was freaking out similarly to you, but you got this. Good Luck!