What are the signs for when to place someone in memory care?

My mom has been increasing in her agitation of living with me. She is back to protesting taking her meds. Complaining about the caregiver (and the caregiver is doing a great job keeping mom's room clean, laundry done, meals prepared, etc). I also have a camera and can see what happens in my home when I'm not there.
I'm concerned that because my mother is not listening to me, she will get worse if she stays "protesting " everything I say. She will refuse to eat what I fix (even though it is the things she likes). She swears I'm trying to harm her and she is the one lately hitting me when she gets mad. I walk away and tell her that it's not nice to hit people and if she keeps it up, then she can't be my roommate anymore. She doesn't care what I say to her. She is always threatening to beat me. I believe she sees me as a child and so she can't take me "suggesting " things to her. There are days she doesn't wash, but she thinks she does or I'm "disrespectful" for even suggesting that she washes. If I can't get her to take her meds then what do I do? She is diabetic (managing through food and exercise which she has not been exercising in months and I cook because she can't). She also has high blood pressure.

I got a list from her case manager to look up memory care facilities and started calling last week. Do I need to be ready to move her in 3-6 months or is this another phase? FYI, my mother has always been a selfish, stubborn, controlling and mean person. Now, this seems to the 3rd degree!