Hi,
You answered your own question. If he could hurt you it is time to get help. My wife had Alzheimer's 14 years before passing. There were times of violence and one must be careful. Be caring and comforting and just back away when you feel he can hurt you. Their mood can change quickly as they don't remember the time of anger. This illness is devastating to a caregiver. God will help you through it.
Fred

Its time, you know it is. If he is scaring you, you do not have to endure that.

When you talk to him try being pleasant and caring. Talk softly. Tell him you love him and see if there is a response. Be careful about facial expression. My wife could see the frustration in me. She didn't know who I was or that we were married. She could see the frustration and stress in my face. Relax and hopefully you may break through. In the end, I knew she loved me. Good luck.

My loved one is in Long Term care now. Up to 10 days ago everyone was on a hate list except me. But the last 3 times I visited he now hates me. Yesterday he would not answer when I talked to him. I took care of many patients with dementia in my 62 years of nursing but this is different. As a nurse, I can be centered in reality but as a wife, it hurts. Would like some feedback. Blessings to you all.

Good question! My mom only weighs 106 pounds but she does cause pain with slapping me, throwing objects and her cane has made dents on furniture when she is mad.