I have only just caught up with this so please accept my sincere condolences. I am so very sorry you went through such an ordeal but even though you found it so hard (as any of us would) you still struggled on and did the very best you could, without training, time off for good behaviour and with little/no support. Please don't feel guilty, his illness was not your fault. What more could you possibly have done for him?
I hope soon you will be able to think of the happier times you had with your Dad.
Big hugs, Sharon x