Do not berate yourself, no-one could/is trying harder than you to support not just your dad, but mum as well.
This won't have any bearing or help with your dad's case, but as a matter of interest, are there any other families having similar difficulties with the CH at the moment or in the past?
The CH general attitude seems so lax, it would seem likely that other people have been there before you, is so, are you aware of the details/outcome?
(I know you're in the depths of despair with your own problems, ignore my comment about other pwd residents).