You're the opposite of me. I am the queen of delayed reaction. Something will happen and I do register somewhere in my mind that *something* isn't right, but what that something is and how I feel about it might not occur to me for hours or even days. Or even I can talk about something that bothered me outright and hear the other person explain it to me and I'll feel fine - then BAM! two days later I realize their explanation caused me to be more bothered than before.
I wish I could be more like you rather than giving someone the impression that everything is cool only to have it clearly form at a later date and leave them feeling blindsided.
Just tell him you appreciate the apology but that your hurt feelings don't insta mend. Is there something he could have said/done differently that would have made you feel better right away?