I would say that I understand that polyamory isn't working for her any more, that she doesn't have the resources to maintain multiple relationships at this time, but I do. I'd remind her that we always had a poly relationship and it's unfair to expect you to change. However, she is free to date as she wishes and you understand that needs change. Her need may have changed and you acknowledge that your needs may now be incompatible and that's sad, but pressuring one another to consent to something that makes them unhappy is not going to create the healthy, happy relationships you both strive for.
Please forward any comments, complaints or suggestions about my various thoughts and opinions here