I am so sorry. I know you are devastated.
As a doctor, you may already know of this resource but I'll post the link just in case. While it is a forum provided by alz.org., members discuss all kinds of dementia, share experiences, ask questions & give advice. There are separate sections for caregivers, spouses, patients, early-onset dementia, & info on trials (but anyone is welcome to post anywhere).
I found it invaluable for information & support.
https://www.alzconnected.org/