I feel you , I went through similar with my mom, she was not as bad that she did not know me, but she would go out from the house and not remember how to get back. Her and my Dad were two peas in a pod, they were for ever fighting and accusing each other of cheating at cards which they loved to play with each other. Yet they could not stand to be apart. After my Dad passed away my Mom lost her will to live, she just wonder around aimlessly. It was sad to see, could not be with out him. she did not live long after he passed .
I have taken after my mom in most things which as I get older and start forgetting things that I should know makes me nervous.