Autistic parent

My father is going to be 80 this year. Of course he is undiagnosed his generation has no idea about atypical neurology. So it means that there are also very few papers or researchers into what it is like for a grown child to have an autistic parent, who is furthermore undiagnosed full stop it is like living with a tyrant. It is like living with a bully. There is no space for anyone but him and his rules and his regulations. If any of the rules and regulations are crossed in his mind he uses emotional violence to make sure everything stays in his place how he likes. He refuses to to update anything and keeps things for decades which means that we are living in a house filled with ***. There is no space for anyone else and when we we suggest the possibility of clearing out he has a meltdown

I understand that maybe I'm in the wrong for him here and that I need a forum for children with parents with autism but I am at my tether and I do not know what to do do. Of course the way out is to simply leave, "it's his life, leave him to it" but for a temporary time I am actually living with them. I see in my mother's eyes dread and fear anger and hatred to his absolutely unbending abusive holding of power.

Any suggestions? Any help? Anything? How to make someone aware that he is not the only person who exists in the world?

I do apologise if this post seems aggressive, but I really am at my wits end. I have been kind I have been open I have been understanding I have been empathic for months. I'm in burn out.