What a sad and painfully frustrating process this whole mess must have been for you! Damn, that really stinks! Lots and lots of tough stories like this one- many folks have passed alone and in the hospital/nursing home without being able to see loved ones over the past couple years. Shitty deal...
One thing that MAY be helpful for you, if you're ever in a similar tough situation, is to demand a case manager for your loved one. If you get one, I've found them to be very informed and super helpful. We had two different ones through the process of my dad's death and hey were absolute angels to us. They helped us in countless ways- both were kind, compassionate, and super informed on how to deal with things as they came up. I was impressed and I'm forever indebted to those two wonderful gals.
Also, the Dr. you were stuck dealing with (or not dealing with) sounds like a real tool. He's probably over worked and completely exhausted, but to refuse to talk to family is inexcusable IMO. I'm not a "file a complaint" kinda guy at all, but if that happened to me, I'd be filing a formal complaint. Likely wouldn't do a lick of good, but I'd do it anyway.
Most importantly, I'm glad your dad is on the right path! Good luck to him and to you. I hope he continues to improve and stays healthy for many years to come.