Hi Chrissy,
I was exactly the same as you....besides the juggling....lol! Kept playing questions over in my head and getting memory freezes, i think its just nerves that make you panic. The 2:1 isnt until the afternoon at the interview so the crew do everything they can to try and calm you down before u go into that!
You wil be fine, try not to over prepare, it will only freak you out
hehe!
Just be yourself and smile, and if in your interview you do get a memory block for a while its not the end of the world (I did in the one other interview i went to and still got the job!)
Good luck hun - its nowhere near as bad as u think its going to be (trust me i know! hehe!)
x Jade x