So sorry to hear that Marra, i can only relate to a point as i cared for my Mam through this terrible disease, i can’t even imagine how hard it must be if it’s your partner of 50 years, heartbreaking. What i do know is that the respite breaks are important, you can only care for your Wife if you are fit and healthy yourself, easy to say but hard to be at ease with as per your post. Take care Marra and good luck to you and your good lady.
It sounds like you have loads of fantastic family support but remember plenty of support on here if you need it, they are all a fantastic bunch and one thing i’ve learned is they step up for one of their own.