First, I would suggest you get a consultation/second opinion with another professional-just to make sure the diagnosis is correct. I am a speech language pathologist-retired now. I have seen people with dx and second opinions revealed a different result. My good friend’s husband was dx with dementia and she began to interact with him based on that. She wouldn’t let him drive, etc. Turns out he was severely depressed. Not trying to give you false hope, but I would want to be sure.
I suggest the next step is counseling for you and your children. They (and you) may be grieving and need to work through that before they are ready to explore how to interact. The dementia will still be there when they are ready to learn more.
In my years of working with families of people that were younger the refrain that was repeated over and over was, “It’s not fair, it just isn’t fair.”
Of course it is not fair. It is never fair. It wouldn’t be fair if she had a brain tumor, or got a traumatic brain injury from a car accident. Most people get to grieve after their loved one passes. But with dementia you grieve while they are still living.
You sound like a wonderful caring husband and father. What you are facing is very very hard, but not impossible.