Hi Jannar...your story could be my story...in fact, most of us here have felt those same feelings you're having!
What you describe about the repeating...paranoia...blaming you for her situation; that's what this horrific disease is all about. Part of her does realize the changes going on that she has no control over...and YOU'RE the closest "target" she has. At the beginning of my Mom's disease, I seemed to be who she was most mad at...and sure questioned my own sanity for driving the hour to see her every week! The first 2 years were awful!
The progression of Alzheimer's will soon make her think she IS already home...and memories of walking and the garden will cease to be.
I have had to think of this as "an interesting disease" in order to continue any relationship at all with Mom. For 10 years I have made the weekly drive (Toledo)...she has not known who I am for several years...but, even now sometimes will give me a spectacular smile and make a kiss shape with her mouth...she does know I'm someone who loves her.
I remember pledging to myself that I'd never return after particularly awful visits where she'd curse, hit, kick, or spit at me! After each visit, I felt drained...and cried most of the way home...............but I'm glad I did not quit visiting! There will also be warm visits that will surprise you with happy tears.
I wish I could help you realize this is just the start of a long journey...it will be different.........Pam
(I see you're from Jackson...the fella I work with drives from there every day!)