I'm too good for such treatment, so I am rejecting it.
I never once rejected him, though. Never once.
I think you're doing the only thing you can do. For a while, when my sister was a few years younger than your son, she intended on just leaving and never having contact with family again. It had NOTHING to do with anger or anything. She just wanted a clean break, to be separate... sort of like she had no past. I don't know what the motivation for that is, and I let her know just how much she would hurt everyone were she to do so.
Anyway, she outgrew that desire before doing it, so I think it was just a phase. Perhaps your son is just a few years more immature than she. You know best. But for both your sake, I hope he comes to his senses sooner, rather than later.
Tammy