I am sorry you might be suffering break up pains. That's never fun.
I am glad you are moving toward exercising your ethics more. That's a good thing, even if you have to travel through stuff to arrive.
When you date next time, you could be more up front about what it is you are seeking and better look out for your own mental and emotional health and well being. Maybe just state what it is you WANT. Not merely what you are willing to "accept" as ok, but what you "actually WANT and can thrive
Using this article
as a talking point? Could be more clear with your dating partners in the dating process before sex happens or things get emotionally serious.
I'm just not up to getting attached to a stream of folks and having them then leave my life. I'm just not up for casual. "I am not up for a (3) model where the polyshipping people are "Non-primary and Open." If you seek this model, I'm not a good potential poly partner then.
I like attachment and want stronger ties/bonds with my poly partner(s). I could be up for a model where it is more like (1C, 2A, 2B? -- you decide and put in here.)
I could entertain the thought with you and talk about how that could play out for us. Could you be willing to discuss?
So much easier to just spit it out there. You are responsible for knowing and stating your own wants, needs, and limits. You are responsible for you own bet healths and well being.