My partner completely forgot who they are.

My partner has DID, and just had what looks like an episode. They now cannot remember their name, where they live, where I live, who they are, when they were born, who I am, nothing. They cannot remember anything and I am doing my absolute best to restore some memories to them. I’m not sure how as I’ve never been in this type of situation- other than myself having brief anxiety-induced amnesia, though it resolves within a day and has not ever been this bad. I’m very worried that I may not be able to help them. Can someone please, PLEASE give me advice on this?