I haven't tried DEARMAN. I can never remember it in the heat of the moment.
Don't be too hard on yourself... .I can't remember DEARMAN even on the good days!

What I have learned from lessons is to lather, rinse, repeat. Repetition has helped me form (good) habits. I don't just use the tools with my husband, I've made them part of my life and it's helping me stay calmer in all kinds of situations.
I'm not sure what will help in your situation, but try different tools until something strikes a chord and feels natural for you.
Wishing you peaceful days ahead!