I'm sorry you've had the double whammy of caring for you Mum and then the signs you've been trying to deny for years fall into enough of a pattern for the PD diagnosis. What's worse in many ways is that what you've learnt helps your Mum can't simply be adopted by you.
However, it can be adapted. Look back at how your Mum's symptoms were investigated, how the drugs were chosen and how they are meant to help versus how well they do help. It the communication of your symptoms that's key in getting both the medication and timing right for you.
Sleep issues are related directly to your dopamine state where your body can rest. Investigate your med timings related to day time drowsiness, then replicate near your ideal bedtime.
You've already identified the most important activity is being active. A word of caution though, the key ageing factor is muscle mass loss, not getting your body fat below 15/20 M/F. If you feel like your exercise is 'killing you' it most likely is. You should feel toned and flexible within an hour of finishing. If you need ICE baths or feel guilty for eating a small bar of 'whatulike', LIFE has become a chore. Simple body fact, if you crave salt, butter, cream etc. your body is telling you you've depleted the reserves too far. Like PD, everyone has their own 'comfortable' zone. Just try to spot the 'I'm satiated' phase when eating when the flavour isn't as intense, then stop and plate up less next time.
I am 55 diagnosed 11 years now and my energy / fatigue levels are currently at their highest / lowest for at least 15 years. Since the new year I have begun exercising much more and WALK (for Golf) about 20 miles a week. I do NOT hideous amounts of unrelenting aerobic running, cycling, cross trainer. I do 90% of my weight limits on the resistance machines as hard as I can for 30 - 45 seconds. I then rest for 1 minute and go again on the next machine that uses the opposite muscles in the same limb. I keep my heart rate up around 130 on average but if I'm out of breath I rest until it's below 100. In a typical 1 hour inc. 5 min warm up and 10 min stretch I burn I burn 800 calories. I have removed 4 inches off my waist, I'm a stone lighter and even more scary, I can say 'I'll have that choccy later or only nibble a bit , not the whole bar. Not quite there on biscuits, which fall out in batches of 4. Must be how I hold the packet...
Life has become a lot more 'opportunites' not 'limitations'. I still have nearly half the day when I'm in various stages of OFF. But when I'm ON I'm FULL ON. (getting carried away now).
What happened around the New year? When your symptoms start appearing like they were 2 years ago and your meds are being reduced, something is going on. It's becoming obvious to many that I'm really really positive. There's a little while to go before more can be said....