heatherweh, I am so sorry for what you and your family are experiencing.
I lost my father to OCPD last October, right on my mom's birthday. He had been at home and for the last 6 months had been grieving heavily for my brother, his first child, who passed away before him on Earth Day, 6 months prior to my Dad's death, of lung cancer. He had really suffered with his OCPD in those last 6 months, the grief was just too much, and he wanted little help. He was bitter, I think, and perhaps his pride got in the way too. He passed away without warning, and I never got a chance to say good-bye. You are blessed to have had those moments with your Dad. I still grieve for that loss.
It has been harrowing, and I just keep doing my best to be present and move forward, as I have my little ones to think about. I feel like I am healing very slowly, and I accept that. All in due time, I think.
I would encourage you to try to support your Dad with meeting his needs in the (seemingly by your description) crummy place he has to spend his last time. He should have access to at least one caring person as he prepares to leave. It's only right. No one should ever cry out to be helped and have no one come. That is heart wrenching to imagine. You can find the strength, allow your little ones some time with a movie or whatever, to assist you with phonecalls. It can come together. Your Dad needs you to help. I will pray that his needs are met, and that he is not alone, if he doesn't wish to be during his last piece of life. My heart goes out to you, and try to stay strong, for your little ones too.