You don't fool around, do you? Jeez, there is *no one* not anxious, never mind SA, going to a panel interview for a job. Wow. You should give yourself lots of special rewards for whatever steps you take in this process.
Do you not have anyone who could travel with you, to give moral support? Or, you could set up people you could call to check in periodically on the phone, to tell them how you're doing.
I was going to take a workshop a couple months ago out of state, and I knew: strange city, strange people, staying overnight in a strange place. So I decided I would travel by plane one day early, and allow myself time to rest in my hotel room, and then I'd have plenty of time the next day to show up for the start of the workshop.
I didn't actually go, but, this might be an idea for you, if you can fly one day early, then you can have time to rest so you won't be rushing right into this big interview, which is not a good idea.
Well I wish you good luck! Take care of yourself and remember whatever step you take, that's effort you made. So you can feel good about that.