I am so very sorry that you are battling this with your much loved son. It is very clear how much you love him. No one homeschools that many kids without loving them deeply. I homeschooled my kids at various points in their education, and I only had 3 kids. I cannot even begin to understand how you deal with an adult who had drug issues while homeschooling your other kids. Sadly, right now he is determined to not follow advice to get clean and sober. You can only do so much for him. This is his battle and no matter how much you want for him to win this battle, you have no real power. It is pretty common for the family of addicts to want the addict to get clean/sober and to have to wait a heck of a lot longer until the addict wants to be sober/clean.
I urge you to stay on the same page as your spouse. Not because I have great recommendations to cope with this, but because if you are not united, he will just triangulate and pit you against each other for his benefit. Not good benefit, to get more from you to help his addiction.
Addiction is a family disease. If one member has it, all are impacted by it. You learn unhealthy behavior patterns that you simply don't see, or don't see as unusual. Having family that goes to AlAnon or NarAnon (the meetings for family members of addicts) is incredibly good for the entire family. I would encourage all of your other children who are 12 and older to go to AlATeen. Those meetings are for kids to talk about having an addict in their lives. Did you know that if your family gets healthy and draws healthy boundaries, it increases an alcoholic/addict's chances of getting and staying sober by 30%. If this were a school grade, many of us would sit through a 1 hour a week meeting if it increased our child's chances of getting a good grade. I think just as much emphasis should be put on recovery. Without recovery, it doesn't matter how educated someone is. To get an idea of some of the unhealthy behaviors that families can have, I strongly recommend "The Laundry List: The ACoA Experience". ACoA means Adult Child of Alcoholics. That describes a lot of people who don't drink/use, but still have learned behaviors due to growing up with addicts in our families. I am an adult grandchild of an alcoholic. I am also the sister of one, the niece of another, and I could go on with the bajillion cousins on my dad's side. But no one wants that list. It is a long road to realizing these behavioral patterns through to help and a healthy life. But it can be done.
I do think that having your son living at home would be detrimental to his siblings. You have to make them the priority. Your son is an adult who needs to realize the problems his choices create. He is also an adult. And responsible for himself, at least legally. Your other children should not be exposed to his addiction up close and personal. Often it takes having no place to go to in some nasty weather and circumstances to really hit bottom. For some not even that is enough. It isn't a choice you get to make for him. He may need some support, but if possible, keep the support minimal until he sees that he needs real help and he is willing to put in the hard hard work. I completely understand both cutting him off completely, and providing some help based on what is right for you and his father, or either of you.
