Same rules apply ... but in a different way
I think the same rules apply in all the different forms of poly there are and in all the different forms of mono there are - if there's something going on in your relationship that you don't like / doesn't work for you / upsets or hurts you, you look at the big picture (analyze how everything else is working, pick you battles, consider how you feel about your relationship partner, etc), then you talk to your partner. You share how you're feeling - in a reasonable, adult fashion (as I'm sure you would do). You ask to be heard. Then you listen, as they share what's going on with them, how they see the situation, and what possible limitations they might be experiencing at the moment. And, finally, you negotiate. Or you don't negotiate and then you face a decision point - stay and wait it out, keep fighting for what you need and wait it out, or leave.
I will say the same thing I'm sure you'd read on this forum 1,000 times - they best thing you can do is communicate, hopefully in a positive constructive manner, then see what happens next.
Good luck to you. I'm sorry you're hurting.