My husband is 74 with vascular dementia. We've been married 54 years. For a while he has been thinking on and off I am his mother who passed away 48 years ago. Then he starts looking for his "girlfriend" Peggy (me). He keeps calling my cell phone looking for her. If I answer the phone in his presence, he gets mad and says "mom" has stolen Peggy's phone. I have tried different things to kind of reset him, sometimes leaving the house, then when he calls Peggy's phone and asks when I'm coming home, I tell him I'll be there in a few minutes. For a while that worked. By the way, he had a terrible relationship with his mom, she was an abusive alcoholic, but it seems like he wants to make amends with her when she "shows up". If gis mother was alive, she would be 96.
When I get back and he realizes who I am, he wants to know why I don't answer his calls and he hasn't seen me all day. I know we are supposed to play into their world, but this is not working with all the phone calls. It does help when we get out or if one of our kids call, he snaps out of it most times, but when we're alone, it starts all over againThe doctor has tried switching some meds, but nothing helps for long. I had one day in the past week where he knew who I was for a whole day.I know I can't reason with him, but the other day we couldn't go out to eat because mom wasn't here and we had to ask permission to use her car first.A switch will flip in his head several times a day like this.
https://www.agingcare.com/questions/my-husband-thinks-that-i-am-not-his-wife-and-throws-fits-if-i-tell-him-i-am-498197.htm
My dad had frontotemporal dementia, which doesn’t usually involve memory loss until close to the end. He never forgot who I was or who my mom was— people he saw daily. But others he would mix up at times. Like he thought my son was my brother.
Your husband's mind seems to be stuck at a point in his youth when you were also young. He thinks your his mother because you are older now and live with him, as he lived with his mother who was older than him when he was dating the youthful you. But keep trying with his doctor to find the right dose/combo of medication that can help relieve his anxiety, at least.
When moms dementia advanced, she stopped all the obsessing about the dead relatives, thankfully, and she relaxed and became docile for once.
With dementia, they revert in time back to when they were young. Your husband expects you to look like Peggy did when you were young and dating, so it confuses him to see you as you are now. Remind him his mother passed away years ago, and you now own your own car. If it upsets him to be reminded of his mom's death, then tell him therapeutic fibs about her instead. Whatever the situation calls for, that's how you handle it. It's exhausting.
You may want to turn your phone off if he keeps calling you, or make his "disappear" conveniently. If DH insists you're not Peggy, tell him you're the new helper there to assist him.
I recommend 2 books. Understanding the Dementia Experience by Jennifer Ghent-Fuller available on Amazon, and The 36 Hour Day which is more of a reference book to use when you have a question about a specific thing relating to dementia.
Consider placement in a Memory Care Assisted Living facility if things become too much for you. You matter too. Respite is important for you so hiring in home help is a good idea.
Best of luck with a difficult situation.
At first glance of your question, I thought I would have something to contribute.
My husband also seems to see me as his mother at times. Not literally, but in his mind, I am a mother figure, and he is a little boy. However, our situation is a very different one! My husband is non-mobile, confined to bed, or moved, by me, to his recliner. He is mostly non-verbal. He mumbles a single word or two words to express what he wants, but non-conversational. I change his diapers, dress him, literally spoon feed him. I can see why he feels like a child and I am his mom.
But, it seems your husband has reverted mentally to a point in time when he was a teenager or young adult.
As you say, you know you can't reason with him. As heartbreaking as it is, I think you just have to learn to let it go. Trying to correct him is futile and will probably confuse him more. I think you just have to go along with him, and not worry so much about "explaining" or answering his questions. He won't remember anyway.
If I were in your shoes, I think I would simply state to him, "I'm Peggy" whenever he is asking for her, or calling you mom. Without making a big deal out of it or turning it into a confrontation. I would see if that jogs his memory and if it seems to upset him more, then I would discontinue.
Your life is changing dramatically. So is his. Having a "normal" day together and going out to eat are not likely to happen now. It takes some adjusting to this "new normal" that has become your life. You can grieve, cry, be angry, take a lot of breaks from him. Try and make the most of your time together during the good moments, which will become fewer and farther between.
Start now looking at Memory care facilities in your area, so you can be prepared if/when the time comes that you can no longer manage his condition at home.
One tip I can offer; create a consistent daily routine. The same activity at the same time every day. This will help to calm his brain. He is seeking something familiar. When the days all start to feel familiar, he will be more comfortable.
You are the constant - you are always there. In whatever role or capacity he sees you, he will know you are someone who cares for him and is there for him.