I too suffer from fatigue and disturbed sleep, and I think it's partly the medication and partly the underlying condition. Unfortunately there's no silver bullet.
I've found that whilst my physical symptoms are largely under control (in my case I take a dopamine agonist), the fatigue is tough to deal with, especially at work and on long drives (as an aside, once you are diagnosed with PD you should inform DVLA and get issued with a medical review licence otherwise yout insurance will be invalid).
The key is to pace youself. I have 5 rules:
- Early to bed: 9:30pm most days
- Out socialising one night per week max
- Regular exercise: I try to bike at least 3 times per week but also use the stairs whenever I can etc.
- Work from home one day per week if I can
- Healthy diet: lots of fresh fruit and veg and max 1-2 units of alcohol per day
I also often have an afternoon nap at weekends; a lot of sleep specialists say this is a bad idea but I think it works as long as you keep it to a 20-30 mins power nap.
Hope that helps.