This is a tough one, that takes practice and mental discipline.

You’ve already acknowledged that you can’t change how things ended with this individual. Right now, you’re in a very natural place for humans to be: you’re feeling powerless, like someone has done something to you, and you want to blame that other person for how you’re feeling.

The bit that takes practice and discipline is that you CAN change how you choose to react to things like this. You can take accountability for your reactions and emotions.

Why is this irritating you so much? What is it about the exchange that annoyed you, and makes you wish you could reply? If you had the chance to reply, would you want to do the same thing - reply and block - or continue arguing? To what end? What outcome is it that you want?

Accepting reality starts with acknowledging there are things you can’t change. You’ve already said that, so you know this is the right path to continue going down.

The bit you need to try and take accountability for is understanding why you’re feeling the way you are. This isn’t about the person “robbing you” of the chance to reply. It’s about why you feel so strongly that you need to reply.

Until you know why this pissed you off so much, you can’t take meaningful steps to getting yourself into a better emotional state.