I think it sounds like you're under medicated.
You've had P.D. 8 yrs now and thats a bit much expecting you to go from 4.30pm till morning meds unmedicated.
Perhaps you could try adding another levodopa tab of an evening so your body can rest better then see how that goes and then report back to neuro your result.
Wendy gave excellent advice. The adding on of small amts are what I've been doing in recent yrs too with a fairly good outcome.
Best wishes.