Hi
@Angtrog, and welcome to Dementia Talking Point. This is a very supportive and informative place to be.
Does your husband get more confused as well as tired in the afternoon? If so it could be 'sundowning', which often affects people with dementia in the afternoon. That's the time a person with dementia (PWD) often can get restless, want to go home or generally seem more muddled than usual.
I also think trying to make sense of a world that is making less and less sense must be tiring. I'm deaf and if I have to concentrate, in a meeting for instance, I find it wears me out, and I imagine it is similar for someone with dementia.
Do have a look round and read other people's posts, you'll pick up lots of tips and find loads of support.