How to manage the costs of a memory care place?

Middle income, thrifty, I am now 80 and my husband is 82. He has traumatic brain injury from a bicycle accident. First few years, he was like his old self, reading, following news, walked with difficulty but we took walks together. Two years ago, he lost all sense of time, can't tell day from night, hides food and binge eats. MD says he, once an academic, now has cognition of a typical person his age. No help with dementia diagnosis there. He has become really mean at times. It can hit all at once after a few days of my placating him. He demands I get up middle of the night and make breakfast. Pouts if he doesn't like the food, or I get behind on laundry. He is really scary at times. I find myself hiding a hammer or kitchen knife fearing he might grab it. Or find myself trying to have an escape route out a window if necessary. This is sick thinking. We have too many assets for Medicaid, but only enough for two-three years for him to be in a care facility. I am not looking for a way out of caring for him. But he does frighten me. I would live in a buffet apartment in a poor area, truly, to find some peace which is all I could afford on Social Security.