I understand your concern but you're getting way ahead of yourself. Galileo's answer is excellent and, hopefully, will be reassuring to you. IF it turns out that your Dad has prostate cancer it is most likely slow growing and he has time to evaluate a number of excellent options with a high probability of cure.
In the meantime, as a father myself, I can assure you that the last thing your father wants you to do is freak out about this. I'm sure he would want you to stay focused on your job. If you want a good primer on PCa, I suggest you read Dr. Patrick Walsh's Guide to Surviving Prostate Cancer which you can get in any bookstore. It will give you a good basic education and knowledge is power in this arena.
So, try to stay cool and feel free to come back here with any questions you have or...better yet...encourage your dad to come here.
And, by the way re the biopsy, many guys have no problems at all with them but others have some pain. Mine was done under IV anesthesia so there was no pain at all. But, even if his doc doesn't do it that way, I suggest at least some local anesthesia or calming drugs to make the experience less traumatic. Also, there are a few post biopsy after effects like bloody ejaculate....not painful but pretty nasty looking...that your dad's doctor should tell him about.