Adr6824, this is something I wished I had done while my parents were still alive.... a family tree. I use Ancestry to help with my search now, and it has so very fascinating. It can help to fill up those empty hours.
I don't know how far into Alzheimer's/Dementia your Dad has reached, if he still has here-and-now times, he could possibly remember names to help you along. And if there are any family photo albums, he could give you names of the people in the photographs. And that will give Dad to do, too :)
Do what I do. I taught myself to knit. (I donate the hats I make to a local charity for the homeless) I read. I journal. Can the person you care for either be left alone for a short while, or can you get a companion/ health aide to come in for a few hours a week so you can get out? Can you explore working from home to make some extra cash?
I don't know how far into Alzheimer's/Dementia your Dad has reached, if he still has here-and-now times, he could possibly remember names to help you along. And if there are any family photo albums, he could give you names of the people in the photographs. And that will give Dad to do, too :)