I can see your frustration. The people who assess whether or not we are eligible for PIP have absolutely no concept of the challenges that face us every day of the year. They will see us when we are fully medicated and just about able to face the world.
What they do not see is the inability to get out of bed without taking a large quantity of drugs, waiting sometimes an hour in the morning before they take effect and then trying to lead as normal a life as possible whilst knowing that you are going to be completely exhausted by the evening, unable to sleep which will leave you even more shattered by the following morning - ready to face exactly the same problems. In the meantime, we have to hold down full time jobs just to nmake ends meet and to pay for the additional costs that we all have to pay for the privilege of having PD (fitted shoes to stop the curled toes blistering, physio which is never available on the NHS, osteopath, chiropodist, more frequent dental care etc. etc.)
Life with PD is challenging to say the least, but the harder you try to live with it and not be a burden on society ,the least likely you are to get any help.
Sorry if I also sound rather bitter, but have also had a bad day with people making no allowances for my slowness and stiffness just because I am young for PD and dont look like I have anything wrong with me.
Keep fighting for it and in the immortal words of Norman Stanley Fletcher .......... Dont let the *&^%$£s grind you down.