I should say sorry, but...I don't know?

So, I took my anger (and a bit of my sadness) on my friend and expressed quite clearly that I wanted him to leave the chat room we were in. (It was just us two). Yeah, I know..I was wrong and I brought up an old issue that was never really resolved (because he didn't speak about it?) but at that time..I said I didn't want to talk about it and officially resolve it. I felt bad like the 일 after and wanted to say sorry but oddly...I also didn't. So, I don't know what to do. He did say he was leaving the room for a few days but I don't want to talk to him on there nowadays.

So, I should say sorry. But..I think partially why I took my sadness turned anger out on him is because of the person who said words that couldn't be taken back and they normally defend one another so... but still..