In article ,
Donna UK wrote:

Any advice on what to do next would be really appreciated.

That is a problem, at this time of year. You can only hope that it
comes through the winter and reshoots next year, at which point
you can prune it if needed.

Checking on the drainage in the pot is a good idea; we haven't had
much cold, and it sounds more like waterlogging.

Will the yellow leaves now all fall off, or will they remain on the plant
and return to their glossy green?

They will all fall off. Sorry.


Regards,
Nick Maclaren.