Your dad sounds like he is suffering the same as my dad.
He is 83
He is currently in hospital, with urine infection, chest infection and his ankles are swollen.
He also has trouble breathing.
Also he gets very tired and has also to sleep upright and sleeps a lot.
Memory loss is not bad but caused largely by not taking all his medication - he is on 14 tablets a day.
Also recently before admitted to hospital his speech was slury.
I guess we have to get used to this.
Tonight at the hospital he said he was not long for this world.
My brother and I are prepared for the worst. His heart specialist said it could be anytime or it could be in 6 months or one or two years. You never know.