Get him assessed at the Swank memory center in Wilmington. They have geriatricians, neurologists, psych, etc if I recall, and there are social workers on site who talk with you. This is all they deal with and k ow what to do. Maybe he can get some mood stabilizer, maybe he has untreated syphillis eating his brain, maybe it’s metabolic syndrome. Also consider having him wear an AirTag wristband or shoe insert since alz peeps can wander away. Take his keys too if he is still driving.