I`m certainly not qualified to give you any professional advice , hopefully someone more experienced in this field will be able to offer that kind of help for you.
My personal lay mans suggestion would be : Just be your normal self in expressing how you feel , what is troubling you , and how it makes you feel as a person.What your fears are and how this affects your marriage and relationship with your wife .
Your psychologist is just another human being like yourself , don`t be intimidated by his /her profession .Their there to help you .Just be your natural self when discussing your situation.
Sometimes just pouring out your heartfelt feelings to someone can be therapeutic for you .
I feel for you Bro.Take care and don`t stress out about your appointment.
And let us know how you are doing when you are able to .
I hope I have been of some help