Im not sure that much can be said to help but I will say thatI will pray for your dad.As far as hunting goes hunting is not everything but during the good times is may seem as though it is.

http://www.youtube.com/watch?v=Dn8xbzYsayI&feature=related

Hey keep your head up i hunt with a guy who bowhunts every single day and is parilized from the wast down. He still gets around good

I envy you. I got to hunt small game with my Dad about 3x's as a kid. Never big game. Now with that being said I am even a more avid hunter than my dad ever was. I still want to hunt with him b4 he hangs it up for good. Last yr I didn't get that many chances to even get out with a new job and all. Now I'm stoked. I finally made it out bear hunting for the first time and tagged my first. Deer season is just around the corner and I can't wait.
Its what you make of it. Sometimes you have other responsibilties. And as for your dad. He'll come around...... I'm looking for a spot that is wheel chair accessible for a guy that I met at the local pro-shop. And I can't wait until I see a guy that I see everyyear that only hunts rifle..... has a handicap permit to shoot from his truck....... he lost both legs from the knee down in a logging accident. Both guys need help retrieving game but they still get out.
Keep on huntin, even if your dad says he doesn't want to go...... keep asking. Like I said he'll come around
Here's a few pics

Nice bear!