Most things been said already. One thing I tend to do as well is go through applications and do the "so what" test.
FOr example someone claims to have done something, been part of something. The "so what" is what value does that have here, how has it made this person better or advanced them. Have they just put down some of the generally expected statements to make it sound good? Check your CV and see if you can challenge anything on it. If you can get your response ready; you may not need it but preparation is the key. Employers want to know what sort of person you are, not just can you do the mechanical things.
YOU'RE NOT ALONE, the others are bricking it too. And remember that although it may not seem like it the interviewers are actually on your side. They may be tough but they should genuinely want you to do well. They want the best they can get. If you dont understand something tell them and ask them to clarify it.
Well done for getting this far and enjoy the interview.
BTW you say videoconference. Is it just you and the panel or is it a group of applicants and the panel cos that does change things a bit.