Thanks turnip and ali j. I so appreciate your support.

Dad is 90, so i shouldn't be surprised that's he's unwell, but until 18 months ago he was extremely fit and well, looking after himself. Then he declined extremely quickly, and within 3 months, could only shuffle about the house using a rollater. Within a year, he needed a carer to help with personal care, and dressing, and he couldn't write or turn the pages in his newspaper. He could only manage soft food, and developed a very quiet and hesitant voice. It took him five minutes to shuffle from the living room to the kitchen, and he would often get 'stuck' between steps. GP said it was just his age??!! He had numerous falls, but luckily was not injured.
But seven weeks ago, just after lunch, he 'froze' in the middle of the living room, and pressed his emergency button for the local on-call carers. But they were out on another call, so he was left standing there himself, until he couldn't stand any longer, then he fell over.
The GP checked him out and he wasn't injured, but his heartbeat was irregular, so the GP wanted him admitted to hospital. I met the ambulance at A&E about 6.30pm, and he was seen quickly, but there were no beds, so he spent most of the night on a trolley in A &E.
I don't really know how the diagnosis was made of the PD. They started dad off with heart medication, but his heart settled down on its own. Then the ward doctor began talking about pakinsonism, and that they would try him on medication to see if they could improve his mobility, swallowing etc. So dad was put on Sinemet (think that's right)by the consultant. He was in a care of the elderly ward.
As soon as he started the Sinemet, Dad began to be sick, lose his appetite, and choke even on a drink of water, and all this steadily worsened. His voice became almost impossible to make out, and he became weak, unable to walk at all or even feed himself, and this went on for four weeks, during which he lost a stone and a half, with pretty much no explanation.
We got different stories from different nurses, and had to wait a week for an appointment to see the consultant (!), who told us dad had PD. Dad was then transferred to a rehab ward at another hospital, and they have had more time to make sure he eats, and the physio tries to get him walking again. He was also put on a second drug for PD (don't know what) and an anti-sickness drug.
But he's still getting worse, and recently even has bouts of complete confusion. The docs are now saying the PD meds are not helping him! But they can't take him off them, as the consultant is on leave!
I can't believe that he went into hospital relatively mobile, eating, talking and feeding himself, just seven weeks ago, without a diagnosis of PD, and now he's frail and thin, on a drip, barely audible, not eating enough to keep him alive, but WITH a diagnosis of PD. HELP! Sorry for writing so much, but it was hard to answer your questions in a few words, ali j. I'd welcome any guidance, but i fear there's little I can do now.