Parkinson's and shingles

My grandad has recently been dx with parkinson's. we were all shocked by this and know it is stress related, he has also recently had shingles for which he was put on medication that conflicted with his parkinson's meds resulting in hallucinations. After almost 3 months of my nanny looking after him he has been put on more medication which has led to further and more vivid hallucinations, I don't know if it is the Parkinson's, the medication or the fact he hasn't let himself feel better. My family visited briefly earlier today and learned that not only did he disappear in the early hours of the morning leaving the house in his pyjamas he couldn't remember my name and thought my younger sister could drive. He doesn't know why he's living in the house he is and why his children (my mum, aunt, uncle) don't live with them anymore. He keeps asking my nanny when they are "going home". My family now have concerns that this is looking like dementia.

Confused, worried, sad 21 year old here, just out of uni and wanting to start a career but that means moving away, as if I didn't feel helpless enough.

would appreciate some words of wisdom/comfort
it can be dementia , but also drugs or dehydration .
Hi, I really feel your pain! My Dad has PD and has had it for 8 years his diagnosis came off the back of othelmic shingles, we have just been told that my dad has PDD and it is a distressing diagnosis, his behaviour has been strange, he often wanders out in the middle of the night, then we get a phone call from the police or the hospital saying that he has been picked up, he often leaves his flat without his keys, and I have to drive over to let him in (he lives alone) his memory long term is fantastic it is just his short term that seems really poor, he is very quick witted still, and i often look at him and wonder if they are right with their diagnosis, it's very confusing. What I am trying to say to you is, if your beloved grandad was in his right mind he would be mortified to find you putting your life on hold, I still have to continue mine too, it is hard and I do feel guilt, and you will too, but you have to get on with your life, you can still be there for your grandad, you need to go an accomplish your goals in life, because in reality this will make him the proudest grandad in the world. I can't tell you not to feel sad, because I do too, the best way you can honour your Grandad is to live your life, and live it full and large! xxx