It's a generalized loss of personal relations, so...
Those words would fit it if it was about a single person, but it's generalized. So there's nothing to get marginalized from.
I do favor "community dissolution" or on the extreme "society dissolution". You can find similar things in history to take lessons from (it doesn't end well), but you will need to go way further than what you are trying.
Let's see ...
marginalisation? disenfranchisement? alienation?
Just throwing some words out there to see what will stick ... like the big Jee ... oops (covers mouth, runs away)