"How is this fair" ?
With all due respect, what if you saw someone standing out in the rain, unwilling to come in, and crying out "How is this fair? I'm so wet!" For as long as you won't help yourself, you will suffer this abuse from him. It appears to be the way he is.
I got the blame because I allowed him to GIVE me the blame. If he thought I would set boundaries and keep them, he would not have behaved the way he did.
I got it because I took it.
I didn't have the self-esteem to stand up and say, "I deserve better than you."
And when I finally did, I finally found out what joy was.
Consider not forcing yourself and you sweet little boy to live with this, and to learn that it's an okay way to live. You do know that's what he's learning, right? You do know the effect this will have on him as he grows older? (stop in to the ACoA forum if you want to see firsthand how kids of active alcoholics turn out; it ain't pretty)
Have some respect for yourself and for your son, and it won't matter one bit what your A has to say about it. There's NO guarantee that a trial basis thing is going to work, that's why it's called a trial; sounds like this one hasn't, not for you anyway?
Hugs to you