It used to be that when someone crossed my boundary I would get upset, and start yelling. ANGRY! “This will change things.”
It never did. Then, time and again, I realized that the only person I was upset with, was me. For allowing such things to happen in the first place.
So now when I get upset. I simply take a deep breath, and explain to the other person how what they have done has hurt or trespassed against me.
Now it is they who get angry…