Whenever i have a big event or situation im nervous about i try and divert the engery in to preparation.
Planing my route there
What will i wear so im confident and not to hot/cold etc Not rushing about on the day looking for my shirt or getting it Iron at the last moment
Prepare any extra evidence and read though it making sure its organised so i know where every example is.
Read though any application form.
read though others experinces of interviews (a few ladies on here if you ask nicely enough im sure they will talk though how theres went)
Talk to your hubby lots about him his intrests,
favoruite color, foods, where he lives his, his job what he does, his family (but im sure you do that all the time anyway

)
Also its a good idea to try and get exercise/read/cook/eat nice foods/spend time with family and loved ones.