My brother is an alcoholic. He used to be always in the grip of it. Not only affecting himself but those around him. When he ended up in the hospital pretty much at the poisoning stage it had an impact in him.

He has been sober for a year or more now. It is a relief.

Other family members doubt his sobriety but then they never see him. Enjoy your fathers sobriety. I hope that it lasts for a very long time.