onlyitj, I am sorry to hear how disruptive all this is to your life. A lot of weight falls on your shoulders so be sure and take care of yourself.

Having an advocate for yourself and your family could really help. Here are some articles on coping with Capgras delusions
Dementia and Capgras Syndrome: Handling Behavior and Emotional Fallout

8 Ways To Cope With Someone Who Has Delusions | Caregivers, Family & Friends

Capgras and Dementia: The Imposter Syndrome

Part 1: Getting Through To Delusional Beliefs | Caregivers, Family & Friends