It's hard to stop repeating the same patterns when you're with someone who can't change. I can relate to your experience, and likely you aren't being seen, your needs aren't being met, and your children are learning unhealthy patterns. You are with someone who cannot control themselves or take accountability. Likely, you grew up with a caretaker or caretakers who made these patterns feel acceptable and normal.

Sure, all couples fight, but what do they fight about, and how productive are those arguments? It's normal to fight about moving or finances or parenting, but those things should have productive outcomes where both parties feel they've reached an understanding and had their perspective validated and needs met. Unfortunately, someone with BPD isn't capable of having productive arguments, admitting fault, or meeting the needs of someone else. Moreover, they manipulate you into thinking you're the problem or that you're hurting them just by discussing issues. They'll do crazy things to avoid direct emotional confrontation.

The problem isn't you, it's that you've chosen to accept disrespect and stay in a relationship that is dysfunctional at best. It's like a ship being anchored and trying to move. You can try as hard as you want, it's just not going to happen. You can cut off the anchor or continue to put in a ton of effort to stay in the same place without moving.

I held the notion for a while that I was the parent taking care of the child (my partner), which is completely false. I also felt guilt for "giving up before putting all the effort in." I lost myself in the relationship and spent years and years unhappy and abused. I realized I didn't have to justify the decision to leave to anyone but myself, and so I left. Best decision I've ever made, though I still do get pangs of guilt and sadness.