First of all, welcome to SR!
You say you don't want to leave because of your son in high school right now, but I can guarantee that son is being damaged by his father's alcoholism.
When I was married to my EXAH, I was never 'there' for my oldest daughter. She's 31 now, and an active addict/alcoholic.
I'd like to suggest the book "Codependent No More" by Melody Beattie, and Catlovermi has also give you excellent suggestions!
:ghug :ghug