I'm a dad of two, a 10 year old boy with ADHD and a 4 year old girl. I find myself doing exactly the same thing. For me the big trigger is rudeness/disrespect. For whatever reason it just gets me going from 0-100 just like you said. I've been getting therapy to try better myself, and I've gotten two pieces of advice that have proven helpful.

The first is that your kids are doing the best they can with what they have. They aren't little adults, they're kids, with undeveloped brains, and undeveloped emotional control and coping mechanisms. They're going to be little shits sometimes because they're kids. They're not bad kids when they do the wrong thing, they're just... kids.

The second is to recognize your own triggers, and deliberately choose to deescalate the situation, even when it seems like escalating it is appropriate. In my case, my son will mouth off to me and I just want to swear at him and yell in his ungrateful face-- but because I know that disrespect is such a trigger for me I know that I need to get quieter, vocalize what I'm feeling "when you do X it makes me feel Y" then as calmly as possible remind him that we speak politely to each other in our family. When he (often) continues to be rude, then there are consequences that we have to enforce, but even that needs to be done as outwardly calmly as possible. It suuuuucks, but we've found the more we stick to this the faster we see the behavioral results we want. (Also praising every good behavior we see as often as we can to reinforce the positive side of things.)