I also wanted to comment on the fact that your Dad is only three weeks out from a major surgery and still very much recovering and adjusting to the physical and emotional effects of that experience. That alone is enough to trigger major depression, let alone hearing the news at his followup. I'm not sure anyone would not feel much the same given those circumstances because it is much the same as the grieving process for any major devastating life event.
He needs time to process all that is going on internally but keep an eye on him. If the depression worsens beyond what would seem "normal" (if there is such a thing), mention it to his doctor because he may need some meds to help get through it. Blessings to you both...
Best wishes... Catherine
TURBT 1/21/10 at age 55
Dx: T2aN0M0 Primary Bladder Adenocarcinoma
Partial Cystectomy 2/25/10
Vanderbilt Medical Center
Thanks so much. I will continue to use this site for help. Lots of strong and caring people here. To take the time to help others while going through personal stuff of your/their own is a service to mankind. So grateful.