redditors caring for parents with Alzheimer/ dementia; what was the absolute worst part of it for you, and for them.

I my family and I am caring for my 74 year old father and, although he does not yet had a diagnosis, it is clear that something is very wrong. recently he has been having trouble communicating, and getting 'lost in time'. he told me that he doesn't feel that this is his real life, that he has a life somewhere else that he it going back to soon.

I want to make things as good as possible for him, but i have learned how hard caring for him is, and I know it will just get harder. (the biggest problem right now is just that being asked the same question 20 times an hour is just. so. annoying.)

I want to be prepared for the worst, so, reddit, how bad does it get?