My family chose the 'do nothing' rout for my Grandmother. Her mental state was declining rapidly, and she lived with us for the last two years of her life. Based on our experiences, if you choose to go this rout, I have a little advice.

Dont wear yourself out trying to care for him. It sounds like you're compleatly on your own here, and that's not a good situation for you or your father. Caring for someone with declining mental health is extremely demanding and exhausting... mentally, emotionally and physically. Also, it only gets harder as the person declines more. Things they used to be able to help you with, or do on their own, suddenly become your responsibility on top of everything else. You have to watch them, because sometimes they try to do things they cant (like make tea, and almost burn the house down). My grandmothers decline was fairly quick, and she never needed to go into a nursing home. Some patients who suffer from dementia remain physically healthy long after the worst stage of dementia, we were told in that instance a care facility where people are trained for that type of patient is often the best choice.

I'm not trying to scare you, but I strongly suggest you look into getting some in home assistance for his care, both for your benefit and his. Nurses trained in this area of care are used to older people who say horrible things...dementia of many types is common in older people, and can bring out some nasty stuff. That's not really unusual. In Canada we have the Victorian Order of Nurses (VON) who help with this kind of thing. Perhaps in your area there is a similar organization. You'll have to research it.

The other major thing is making decisions about his estate and care while he's alive, but perhaps no longer mentally competent. Do you have power of attorney for your father? You really want to work on obtaining that right. It would make future issues that may arise from your fathers declining mental state easier to handle when they come up.

I'm sorry you're in this position, Op. Its a very difficult spot. Family politics and relationships are complicated at the best of times, but always get worse when times are hardest. Don't forget to take care of yourself too.