hi there Hoprockin!

You've come to the right place, we here know about that worry, the walking on eggshels and the colateral damage we fear our kids will get.
I live with my BPD-GF and she has 2 kids (6 and 11). I didn't have any and we don't have one in common. What is your situation? You said "my kids" and then "their mom", so I'm a bit confused. How old are the kids?
Take some time to navigate this place. There are very important lessons and tools that make life better, for everyone. We influence the family, but we can only change ourselves. 1st we stop adding to the negativity, as you said, then we start puting some bricks for building a better relationship. There are no shortcuts. And accepting that can also bring you some peace.
Please tell us more about your situation. writing about it helps a lot.