I totally understand your struggles. But none of it is these people’s fault. They aren’t obligated to provide anyone with anything.
They’ll drive your guy there and he’ll attend it and they’ll drive him back.

It’s his choice to go. Either ask him to stay home or go with him (stay in a hotel) or let it go.

If your son is in such a bad shape that he can’t function in these circumstances, wouldn’t government provide some services for him? Where are you at?