@cy@mstdn.io
On mutual aid societies, I know someone involved in one (admittedly in Portland). While there is definitely an anarchist protest bent, they've also been doing things like delivering water to the unhoused during the heat and taking people to the hospital when they show signs of heatstroke.
I imagine this sort of group is harder to find the farther you get into the suburbs, but I did see this:
While I'm not one to recommend a church, I understand the Unitarians don't really insist on any particular belief.
NextDoor aims to do some of the things you're aiming for, but in practice fails pretty hard. Most of the posts are either "stop letting your dog poop on my lawn", "I saw a brown person in the neighborhood", or "does anyone happen to have a carburetor for a '62 Buick that I could have for free?". Still, if someone was to announce a block party, that's where they'd probably do it.
It looks like you've tried a lot of things that I might have recommended. Why didn't those work out? I've found, e.g., the gaming community to be very supportive.
People can get into something (as you mention about Pokemon Go) too much, but maybe sometimes what they're getting into *is* community. When a roleplaying group starts they might all have their faces in their rulebooks, but after they've been playing for a few months half the session is just chatting among friends.
I hope these thoughts are helpful.
