Don't get me started with special needs and all that. It's been part of my life from pretty much the very beginning. I was involved with a local group as far back as the early 70s as my grandmother was a director of a facility. I have always had people with special needs as friends. And... my W's job is directly related to this work, as well. I won't get into that... anyhow...
Here's the thing. I don't know the legal jurisdiction you are in, but here, there are laws regarding special needs and so on and so forth. What local or regional resources are you currently drawing on, for support? When a kid that my W and I supported a few years ago reached 21, we advocated (with his parents) his own independent living with full supports and he moved out on his own.
It sounds like your SS21 has similar needs to our friend's S and it was actually important that he move out of the family home, because his outbursts were getting very bad and not just destructive to objects, but to people (his family) as well. But there was NO WAY that we would have him placed in an institution! NO WAY!!!! So we found an alternative. And he has adjusted very well.
Geeze... there's so much I'd like to talk to you about this and it is not even related to your sitch, although I can tell you that your SS21 is certainly reacting not just to his own desire for independence and separation from the family unit, but as much because of the disruption to his "normal" life. He is acting out, and what you are describing is nothing less than what I would expect.
Man... this is one of those times where I really do wish I could direct you to resources to help out. And I will tell you to h3ll with what your W might say about it. Maybe that's not fair to your W and whether she would be supportive. But what she is doing is ABSOLUTELY disrupting your SS21's life and your M troubles are a catalyst to his acting out.
