So many people are faced with this situation I thought you might like to read this article. It's written in a booklet for ALS, which I've always found to have the most comprehensive family-services type material!
FROM DENIAL TO ACCEPTANCE
Taken from A Caregiver's Guide to ALS
If your loved one continues to deny the reality of his diagnosis, you can help most by respecting his expressions of denial, even as you try to avoid reinforcing them.
Recognize an expression of denial for what it is: a wish that things were different.
Don't try to "break through" your loved one's denial, but don't become a part of it, either.
Eventually the person in denial will move out of this stage, and will then be ready to talk about the future. If you have shown your reluctance to help him face the truth, he may be afraid to talk with you now, and even feel abandoned in this stage.
If you have shown your willingness all along to respect his feelings, you will be able to help him even more.