Hi 'out on a limb'. I can totally relate with your situation, as my mum too went through a lot of the same things with my dad, who was diagnosed with PD in his early 40's and remained so for 24 years, although now sadly no longer with us, (6mths gone.
I live close by my mum and even then with the two of us to hand it felt like a struggle on days as you've so rightly pointed out some days you can manage to get out and others not on the bad days, I sincerely understand where you are coming from. Sometimes there would even be bad weeks for dad, and mum would be pulling her hair out with just trying to cope with him and his varying needs.
It certainly does take a lot out of the primary carer and their needs often tend to go overlooked or understated yet to there loved ones they are there 'guardian angels' and rightly so.
My brothers one of which is local to my mum, the other about an hours drive away tended to keep a back seat approach for a lot of the time also until his final month, so we also felt very much out on our own with it all.
Your comments about bills etc, also rang true and is something mum has had to adjust to doing as well on her own now, as dad used to do it all, literally! even with my helping her where I can, it still confuses the pants off us both!
I am not sure as to what extent or symptoms your husband is currently at with the PD, though with my dad, he suffered more with the freezing episodes when walking (apologies, it does have it's name but at the minute my mind is drawing a blank at that one), swallowing problems where he basically had to have everything blended down or extremely soft lump form, and tremors. Yet until his last 2mths he was very much still the intelligent, articulate man he always was. So he became more or less a prisoner in his own body, one that he could always think in, but that failed him in so many others.
Your "brave face" comment also pulls on my own heart strings too, as that is exactly what I felt I had to do when visiting them both, yet inside all I wanted to do was scream at how unfair this all was.
I felt I had to respond to your posting as I can feel your own torment as if it were the same as my own and my mums, and want to encourage you in saying you are only doing I'm sure your very best for your husband and he will know that, and I'm sure very much appreciates it. It oozes from your very words above. It is extremely tough and I hope you are in contact with a local PD nurse for your area as they proved an invaluable source of support and advice for our own family.
Please know that I myself will be here to chat too if you need (or that I can help, or support you) in any which way I can.
I send you much strength and best wishes