AARP Rx majorly covers prescription drugs. Some still have hefty copay but my monthly is under $60 per month!

Talk to your physician's nurse, and get the contact information, or have them give your information, to the pharmaceutical rep for your medication. The majority of drug companies have an assistance program that can get your meds for you at a very reduced rate, or at no cost to you. The drug companies provide this service, and receive benefit from aiding patients, do not be shy. Your Dr can help you. It is not a charity program, it is medication assistance. I am a retired RN and medical administrator for 45 years, and this IS a common request.

Probably not much help but I found this ??

https://www.helprx.info/conditions/parkinsons

Good luck and I hope you can find something affordable.

There a lot of Medicare supplemental plans.
AARP has one thru United Health, Aetna, Humana etc. if you goggle Medicare drug plans you will find several to compare. Hope that helps

You can get a Medicare supliment policy solely for scrips.