Apologizing to a person hurt you, because you did something wrong as well after a while?

Hello, I am looking for advice. I and another friend was friends with a person. I don't really know how to put it into words, but this person was extremely passive aggressive and rude to me during the duration of our friendship. I told the other friend about this, and they confronted the person, and the person recognized that they were wrong, but didn't want to apologize and blocked us all on everything.

I got mad with how they reacted as the person simply pretended we never existed (the other friend was friends with them for a year, and I for a few months). I was heartbroken about this, so I immaturely spammed their accounts with messages. Not insulting messages, but rude messages of what they should've done.

I recognize that me spamming them was extremely wrong of me, as they clearly didn't want to be contacted. Even if they were in the wrong, but what I did after was wrong as well. I should not have done it, and I regret how I handled it. I am hypocritical and let my emotions get the better of me.

I've been thinking about apologizing for spamming them, but I don't know if it's right to do so. I am not seeking for friendship again, but I simply would like to apologize for spamming them. I am still friends with the other friend but I do not wish to dig up old wounds. It's been 3 months since it happened. I understand that what is done is done, but is it too late?