If you are trying to convince me to have nothing to do with my parents, you are succeeding.
I don't know what kind of relationship you have with your Mom...or what the relationship was like between your Mom and Dad.
But some women change personalities like magic if affection is expressed. You might try a bit of physical affection...a little (like holding of the hand now and then or light shoulder massage) or a lot (like a bear hug & kiss every day). Don't get me wrong. You may already be doing this or maybe your Mom is not the kind of lady who goes for it. But your Mom likely is struggling with fears about what's happening; some bits of consistent affection may help her be more peaceful.
My MIL had dementia so I understand a little of what you may be experiencing. Wishing you the very, very best.