I kept seeing a decline in my husband. My daughter didn't realize how bad it was until we moved in with her. His kids didn't think anything was wrong as they only saw him for 2 days about once a year. He was very good at 'showtime'. But that can only be managed for short periods of time normally. And people who don't live through it don't normally understand it. I now keep the tribe updated on how he is doing. Some of his first signs of dementia were having problems with technical things - phone, TV remote, computer, etc. He couldn't fake those as easily as forgetting something.
Make sure to find time for yourself (I started Pilates at almost age 82). Find humor wherever possible. This site is wonderful because you can just let go with all the frustrations and everyone understands - been there or headed there.
I have just applied for Phoenix Dial A Ride for Bill (he can't drive and I shouldn't any more so gave up the car). With Dial A Ride I can go with him as he can't go out on his own. Rarely remembers his address any more. I also use Uber when needed.
Socialize - some caregivers commit themselves totally as their loved one demands all their attention. This isn't good for either of you. Bill won't go to family functions and tries to 'guilty' me into not going (is is fine being left alone at this point). This is something he has always done. I have learned to ignore him - I go and have a wonderful time - and ignore his 'silent' punishment when I get home.

Prayers and good thoughts for both of you.