My late mom had dementia. My late husband and I nursed her to the end.
Our family Dr told me that there would come a time when I would think, "Just hurry up and die."
I was horrified at what he said. He also said, "You don't believe me, I know."
I didn't. I was utterly stunned and couldn't believe our GP had said that thinking that won't be me.
3 months approx before my mom passed what my dr said, came to pass.
I told him this with a rueful smile. He said everyone is the same with this disease. He was right.
I have since advised friends with parent/s with the disease, saying all the things I find out. They, too, thought the same that it would be different for them until they realised it wasn't.
Any health issue can lead you to this. When you're 24/7 under the cosh of someone's health, it affects you too.
It's perfectly normal and does not make you a bad person. It means you're human and coming to the end of what you can deal with. It is the minds way of warning you that it's all getting too much