You answered your own question in part. After years of practice, the thoughts I have during formal sitting meditation have spilled out into everyday life. I find it easier to let thoughts flow through me, which helps me react much less strongly in moments such as you describe. Meditation is one way to cultivate that kind of relaxation. It’s not even control, but rather repetitive practice and habit.

Trying to control yourself in those situations tends to lead to uneven results, because exercising willpower like that tends to be draining and therefore very sensitive to whatever els is going on for you. If you manage to control yourself, you’ll probably want to get out of the situation as soon as possible in order to recover.

I have found a couple of thoughts helpful:

• This moment will pass.
• That kind of reaction (what I used to/typically do) is not helping.

Repeat. Repeat. Repeat. Calmly. With subtle determination.

Of course, none of these are quick fixes.

Peace.