Marcus, I am not a medical health professional, so I cannot advise you. As you may be realizing, this disease impacts everyone differently and some treatments work for some and not for others. I can only tell you what seems to help me and that is movement; walking, weight training, yoga, boxing. Massage has also been helpful for stiffness. I have found that Rock Steady Boxing (designed specifically for people with PD) has been a game changer for me. Here is a link to see if there may be classes near you:
https://rocksteadyboxing.org/find-a-class/
I have written several articles about RSB that may give you some idea of how empowering these classes can be:
https://parkinsonsnewstoday.com/2018/08/21/parkinsons-rock-steady-boxing-mental-push/
https://parkinsonsnewstoday.com/2018/09/04/parkinsons-battle-continues-rock-steady-boxing-classes/
https://parkinsonsnewstoday.com/2018/09/18/parkinsons-disease-battle-complacency/
https://parkinsonsnewstoday.com/2019/01/08/parkinsons-reflections-one-year-rock-steady-boxing-comraderie/
https://parkinsonsnewstoday.com/2019/02/26/rock-steady-boxing-parkinsons-disease-left-room/