I too struggle very often with the pause and the recognition of emotion before acting on it.

Something that has been somewhat helpful to me is a meditation method called mental noting. Please note no method will work for everyone but in case it's useful to you, here goes.

Basically, my version, please do search for more qualified people's version of mental noting on the internet:

1) Rest attention on my breathing

2) Notice (I don't always notice, I don't often notice, but sometimes I do) that I'm distracted

3) Note and label the distraction (mentally say "I'm thinking" or "I'm itching" or "I'm worrying" or "I'm replaying conversation" etc)

4) Thank the distraction for allowing me to flex the mental "noticing muscle"

4.5) Remind myself not to beat myself up about how long I was distracted, haha

5) GOTO 1

This practice has helped me in slowly building up a mental observer that can pause from time to time. But, as I said, I still struggle with the pause.

Speaking purely from my own experience, it takes practice. It wasn’t easy and at first I had no gap between the stimulus and my response. Taking responsibility that my anger is mine and isn’t caused by the other party made it clear in my mind it was up to me to change. "They" aren't "making" me angry; I am angry because "they" have broken some of "my" rules. Sometimes my rules are valid and sometimes not.

The gap widened over time. This is really a process of the heart/spirit/inner goodness, there isn’t any way to think your way through it. It’s about making the commitment to address the behavior, practice and self honesty.

All that said, and all my years of practice, I can still be quick to anger especially in the case of those I have judged to be morons (there's "my" rules coming into play again). But it is nowhere near the same level as what was making me depressed some time ago. And that’s the key point I’m trying to make through my comments here. Look to addressing your inner anger if you’re depressed. Especially when angry with yourself. I want to be really clear I have anger in my life. I do my best to channel it constructively, but I’m no floating in the clouds guru spreading love and unicorn farts across the galaxy. I’ve just found some ways to deal with it and experience some benefit as a result.