I'm groggy because I just woke up but wanted to say welcome and chime in too about how great you've been doing, in my estimation. I was a single Mom too, of a son I brought home when he was 22 months. And I had to call 911 eventually, too. All of the stuff that you are anticipating (my son is 33) has come to be for us.
My son has been homeless for at least half the time since he left my home, and at least half the time he's been housed, it's been at a second home I bought pretty much for that purpose. Even THAT didn't work so well and became the site of power plays between us. Him, trying to impose his rules, and me, trying to impose my own. I see in retrospect this was a huge mistake.
First, it is a developmental imperative that they strut their stuff. And because they see no way to do so in a constructive, adaptive way it is done so negatively. And in my case, I was first, already an older (now old) woman, with vulnerabilities that were triggered. There is no way I should have exposed myself to that fracas, but I saw no other way to love him at that time, and misguidedly wanted to turn the tide. He was the Pacific Ocean and I was a puddle.
Anyway, I wanted to tell you that you are doing GREAT. Your instincts seem perfect. The more we can give them rope, paradoxically the better it is for them and for us.
What changed for me, is the necessary and much-belated awareness we were separate people with separate lives and values and everything else, and that is okay. More than okay. He can be him, and I can be me. And if he chooses to live badly, I can be okay, more than okay. I fought and fought and fought to change him and he fought back just as hard to be who he wanted to be. Now I respect that and I am putting my energy back into being me.
One more thing. My son's major drug of choice is marijuana. I don't like it and I don't want it near me. I don't want even that drug on property I own. And I don't want to be exposed to people who are high, if I can avoid it. I don't feel that I have to change, even in a weed-legal state, certainly in my home and my life.
Mental health treatment, school, medical treatment, and housing, are all available when our sons choose these things.
Honestly, as I look back at this post, it's like I have had a brain transplant compared to how I used to be.