I have had a dreadful fear of Hospitals ever since I woke up in one as a teen with no memory of how I got there (mva). Tell the staff as soon as you arrive how both of you are feeling, especially your partner's fears. They should - if they are worth their salt - work to reassure. Hopefully, pre-op meds can be administered asap and then everything should return to a 'normal' level of worry.
Keep doing what you are doing, stay strong, I am rooting for you both.

Dave.