Kmac,
I just read your posting and it brought me to tears. I know how you feel, trust me.
My dad also was diagnosed with PC, and after surgery his psa was a .55. Higher than your father's. It was horrible, I literally hit depression. He completed radiation two months ago and we are hoping it got everything. You just need to take it easy and be a supportive daughter for him, don't cry in front of him. I did a couple of times and it was painful to see him hurt for me. More painful than anything.
If you need to talk please send me a private email. How old are you by the way?
You dad is in our prayers,
Lynne