Hi, Bruce.
I always have somewhat panic attack before going to medical appointment. It's some kind of illogical fear to me.
Panic will not guarantee good test results but will still our peace of mind. Try to distract yourself with something. When this panic thought pops up, let it go, don't overthink it.
Take a deep breath, relax. Focus on today. Say yourself that you'll panic on the day of appointment if you feel like then, but today is today, and you are not at the doctor's office yet.
Best wishes to you. Let us know when the tests are done.