Hi, and welcome,
You might be better off posting this question over at the
Friends and Family Forum. Recovery from alcoholism is a long road, and it tends to be much smoother with the assistance of AA or a similar recovery program. Quitting drinking can result in extreme mood swings, which can certainly affect a person's sex life.
There is really very little you can do to "help" with his recovery. You can suggest AA, and you can attend Al-Anon meetings (to help friends and family of alcoholics to recover from the effects of living with alcoholism) to help with your own recovery.