Henree low contact was worse for me because she could pop up with demands at anytime. I am glad you have found a good balance though.
On the opposite side, I have had to teach myself not to shout. Anyone who has known me from mid twenties to now, thinks I am always calm. I am not, I appear calm and everytime I get to the point where I want to shout, I remove myself for a few minutes to calm myself down.
It actually has worked well in my career, I refuse to show anxiety, anger or really any heightened emotion. Even though on the inside I am very anxious. The only people who know how I really am is my best friend, dp and Mil. Dp and my best friend are brother and sister and I have known my mil for years, though never met dp for a long time after. She is a great mil and knows how to calm me and recognise when i am not doing well. Probably because she saw me as a daughter before i was was with her son.
My best friend is my total rock and I know I spill all my anxious thoughts to her, she understands and totally gets that after that i go back to my calm serene front.
I don't shout at the kids. I walk away, which was hard at first. But it's easier to see the signs as I feel the annoyance building. I don't argue with dp, when we disagree we are vocal. But if I feel him getting angry or I start feeling angry, I walk away. Dp hated it at first, he felt like I was saying he wasn't worth my time. But he now gets that I need space, always come back and then we sort it out.
I will be honest, it's a constant battle to not be my mum.