I'm really sorry for you, but if you dad does have cancer then maybe you should look into going all healthy.
and no I'm not talking about eating your greens and no sweets(even though that does help

) but going all organic will help your dad sooo much! I swear to you! My mom has gone all organic and that means that she doesn't eat any red meat and not a lot of dairy. If you go to an all organic store you'll find lots of stuff that could help your dad ether live for a longer period of time or maybe even get rid of the cancer completely!
I know I sound stupid but if you had to live with seeing your parents eat fish and brown rice then you'd understand A LOT of stuff in that subject! But I REALLY hope your dad doesn't have cancer..that would be awful!

Best of luck to you and your family!