Welcome back. I don’t know if I can help – you seem to have already decided that “belonging actually is inseparable from my actual physical wellbeing” so you are convinced that your feeling of belonging cannot be changed without endangering your physical wellbeing. As long as that is the case you won’t dare to inquire into even your own feelings of belonging and the need of “playing the emotional games they like playing”.
It’s only when your emotional situation becomes so untenable for you that you are motivated to change it from your end, i.e. unilaterally, and face the “fear around this” that you can slowly work out a sensible way to sort out the situation you have manoeuvred yourself into.
In the meantime, it is good news that you say you “found a surprising amount of contentment and joy even as my life has shrunk” and keep enjoying and appreciating this amount of contentment and joy – and the more you are able to appreciate what you have achieved (without giving way to pride) the more enjoyment is possible.