I cannot begin to stress enough how important it is that you take care of YOU first. You have had SO much on your plate and I realize you are not complaining but the fact is you have had a lot of stress in your life and we all know what stress can do. With that said... my mom has Alzheimer's, was diagnosed over 8 years ago and lived with me the first year. I became very ill and could no longer do it and so she moved in with my sister for 3-1/2 years and now is in ALF for two years. She is at about the same stage as your mom, maybe a little further along. I have two sisters, one is an RN that works at the facility.
What I can tell you about AD is that some of what you mention about your mother is the disease...most patients do withdraw. The disease makes them very insecure. All the confusion and memory loss is scary and can cause severe depression, also anger for all they have lost.
Looking at photos is a very common interest in AD patients. For them, memories of the past are usually still with them and so it is a piece of their lives that they still have. Try to find as many photo albums as you can and when you visit, sit and look at them with your mom. They will probably bring her comfort.
I am so very fortunate. The transition into ALF for my mom was unbelievably great, but my sister does work there and I think that made it so easy, mom knowing that one of her daughters was there. We also visit quite often, my other sister and I, one of us is there every single day and sometimes two of us are there together.
If you have other questions, please feel free to post.
I wish you well
Miriam (I too am "Mimi" )