Go read this article. It really helped me to understand what was happening to my alcoholic husband. He was acting and talking crazy because he's been drinking so long that he was crazy.
The person I married and raised my children with is GONE. There's this shell of a person walking around my house. He looks sorta like my husband, he sounds like him but he's an alien.
The Alcoholic Personality - Page 1
Also you might want to look up things like "wet brain" and the physical
effects of alcohol.
I'm sure your Alanon meetings will also help you to understand what's going on.