Sorry for you loss, Jim...
I know somewhat what you are going through right now as I lost my mother to cancer back in December......
For awhile whenever I went back to dads place it always felt like mom was just around the corner, and I expected her to walk around that corner anytime.....
I moved in with dad to help him out, there's things he cannot do anymore, and I think he likes having the company and knowing there is someone around if an emergency happens.....
More and more it's like the pastor said at mom's funeral.....that we would be full of grief and sadness now, but the time would come when we would all look back, thinking of mother and saying "remember when..." and remembering the good times and laughing.....
It's tough for you now as it was for me back in December......but as time passes things will get back to normal and your father's death will become more accepted as a normal path of life....
If anything it makes one appreciate the relationships that one still has in the present life....things aren't taken for granted quite as much as when everybody close is healthy and alive.....reality comes around and things change.....
Take some time to get over this thing....time is what it's going to take, and believe me, it does get better.....spending some time with the family will help.....and you also have a family at Mad Jacks for some support and wisdom.....I've used them a few times for advice and they have pretty much been right on.....
Take care of yourself....Mark....