How to get over nervousness in new situations

I'm at an infertility clinic with my wife and everything is making me nervous. Words I don't know. Processes I don't understand. Despite only talking in Japanese with my wife I feel like I can barely make a sentence to the doctors. I feel so useless. It's like my mind just becomes blank.

How do you overcome nervousness like this when speaking a second language?

by AdUnfair558