Dementia is perhaps the most cruel disease.
You have my empathy.
About 10 years ago I lost my Father-in-Law to dementia. His last six months were peaceful but he had good loving care. His wife passed away 3 months before his death. When she died the family got together and made a joint decision that we wouldn’t mention his wife’s passing unless he asked where she was. After 50+ years of marriage he never once asked where his wife was for the entire 3 months before he died. I found it interesting how the brain works.