Indulging in confusion

My partner and I are polyamorous, he recently went on a date with someone he’d been talking to on Tinder. I found out that he doesn’t know if she is non-monogamous and has never mentioned me to them. I brought up that this bothered me and now we are in a fight.

C: K said words.
T: He’s trying to hide me.
F: Angry.
A: Feel physical sensations of anger, voice my concerns, feel defensive, not trust what he’s saying, assume the reason that he’s acting so poorly is that he knows he f*cked up, I don’t manage my mind and I don’t try to see things from his perspective.
R: I am interpreting his actions as negative and hurting my own feelings with my thoughts and actions about them. I let external factors change how I feel and I am not allowing myself to manage my mind.

I’m having trouble moving to an intentional model about this as I have so many feelings and so many thoughts about the situation and the fight that followed. I am now questioning if I want to be in the relationship and indulging in confusion.

C: I said words “I don’t know if I want to be with K anymore” to M.
T: I don’t know if I want to be with K anymore.
F: Confusion.
A: Not fully commit to fixing the problem, look for an excuse to “justify” leaving, imagine my life without him, indulge in confusion and not make a decision.
R: I indulge in confusion and don’t give myself the clarity to make a decision either way. I resist the idea of change and let my brain align with the familiar.

I ask myself, if I knew that I could be happy either way what would I do, and I would like to stay but I think deep down I am not sure that I can be happy in the relationship… or maybe it’s that I don’t want to be happy in a relationship where someone treats me the way he does.

I’m a little lost in my thoughts so any feedback and/or pointers would be greatly appreciated!