I feel like I’m in another country and don’t understand the language

Today my DH had a follow up Dr appt for his last ER visit. He told the doctor he didn’t remember being in ER and feels his memory is getting worse. After the visit, driving home, he seemed worn out. He turns to me and says “I think I have it” and I asked what does he think he has and he says I have “it.” It is what his mother had, two brothers, a grandfather and three aunts. I said whatever you have we are in it together. That’s when he said “it’s like being in another country and not understanding the language.” Such an apt description. He said the world is a confusing place and he doesn’t understand it. Such a sad and scary place to be.
For me, feel stressed most days, balancing every aspect of our life, but at the same time, thankful I am younger than he is (67 to his 80) since I have more strength and energy. The emotional toll for me is a bit overwhelming some days as we all know. Missing my children, grandchildren, family and friends.