Just one more voice chiming in. Nothing for you to feel guilty about.
I felt the same way you described about my ex-a-bf. I was losing my serenity, peace and self-respect everytime he got so trashed that he would break promises he made to me.
Your son unfortunately is in the throes of his disease. You are powerless against it. Have you read Codependent No More? I think the essence and the damaging thing about codependency, is that we codies are willing to lose what we hold dear, in order to give everything up to someone who isn't capable of giving US anything. We don't even realize we're actually enabling them. We think we're helping. We're not.
I think if he had been allowed to live on the street, he might realize the consequences of his using. But, he's an adult and not really your problem anymore.
I am so sorry your son and his wife are bringing their children down with them, though. I wonder if you could get temporary custody of them or would even be willing to, since they sound like totally unfit parents.
Originally Posted by
FreeBird09 
Givelove.. I agree, my serenity and self respect is to be solid gold. I seen that once I started losing that balance, things started shifting out of place and it felt as if what I had built up for myself, in myself, was crumbling. I never want to be out of 'peace'. It's hard to accept that my son was using me, and abusing the privilege of being in my home, but it is true.