I am so sorry. I don't know what to advise other than talking to a family lawyer. Regrettably, the highly networked society we have collectively created has spawned its own sort of mass media and cultishness has become widespread because it is easy and profitable to engineer.

I don't know what to suggest for your situation - maybe talk to a family lawyer? I have the impression that the NHS is probably not up to providing the kind of mental health support needed to deal with a broad spectrum social problem.