My parents are still in their healthy autumn years but the only way we've been able to maintain a relationship is when I insisted that there are huge conversations that can't happen; both of us want to talk about some big stuff, but neither of us are allowed to. It wastes what very little time we have together. We have to focus on just enjoying each other's company.
I suggest that you find a way to come to a similar agreement with your dad - agree to leave each other alone and focus on your common ground. Find activities and conversations that you're both happy with, and just do them.