Sorry to hear you are in this situation.
Years ago on EB, the was a great posted thread with what to do - think it disappeared when the member who started the thread had their account deleted.
Definitely get copies of all financial data, and scan & upload to the cloud. Store a hardcopy with family or a friend.
See if you can get a PO box, and start directing all your mail to there - ie change the addresses with companies only you are listed on. eg superannuation account.
Open a bank account and start putting small amounts into it - withdraw extra when you do the grocery shop.