I am so sorry for your losses. What a horrible experience, but at least it sounds as if family is alright.
I agree about making as detailed a list as possible. Because of the amount of your losses, I would sit down with a little tape recorder or someone who writes really fast, and quietly start in your mind at the front door and work in a clockwise manner through each room remembering as much as possible. Every detail from throw rugs to plants to pillows, to ... Put one room per page(s) and continue on. Do also for RV and car. It will take time, but you can do it. Spend only an hour or so at a time so you don't get burn out.
Your in my thoughts and prayers.