Sorry to hear things havent worked out.
I shall pray that you find serenity in the coming days and a solution to your delima that is equitable for all conserned.
Comunication is key in any partnership be that a poly one or otherwise.
That being said it is still sad and regretable but also sometimes unavoidable when people change their minds over the course of time.
I hope that you will find what works for you sooner rather than later.
Good luck.