My Mother gets like this often lately, it's part of the illness. I find that if you distract them and also get someone else involved in conversation it helps. Or if you can step away and let someone else talk them down and then come in as if you just arrived. They tend to feel your frustration and even anger when you think your not showing it and then respond with anger. They may not be able to verbalize very well but they sure can pick up on facial expressions and frustration. I have to put myself in their body and think, if I couldn't express myself to someone because of my speech how would I feel? Also try to play card games, even though it doesn't make sense to you it's doing something that occupies their time and mind. Take 6 cards A's, K's & 2's, put face down and try to match them, don't do too many cards, it's too hard for them. You have to think outside the box all the time with them. And always, always show them your love with hugs, kisses and loving words. I feel for you because my Mother has advanced Alzheimer's and my Father has bad Dementia, but I thank God each and every day that I was able to put them in a memory care facility together, getting their medications and well balanced meals every day plus they are now safe.
Good Luck Ricky, and God Bless you for being such a loving child. ❤️