Lots a good advice here, so not much to add, only to reinforce thr primary points:
Yes, my take is that the wife is quite selfish & manipulative...& the girls have learned well from mom what gets results...
I don't think willingness to go into therapy is a mixed signal, you DO have your son to think about...& I'd say he needs you to be there for him, to give him an escape hatch from that squirrel cage...

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