Here is an excellent article if you are facing anger and aggression in your loved one with dementia.
I was blessed to have almost the opposite. The dementia brought a new positivity to my Mum who had experienced a lot of extreme stress and the dementia brought a kind of oblivious contentment. My Dad also had a very stressful life and the later stages of dementia brought a new sweet, positive and loving side, after the initial anger and frustration of losing control.
Have a read if you are experiencing the anger side with your loved one – https://spiritualeldercare.com/2019/11/18/can-dementia-cause-permanent-anger-and-aggression/#like-4065