Mad at myself

Do you know the feeling when you are mad about something you did or said with yourself? I don't mean that you are mad about what happened, just how you reacted. Well, I know it and I am mad at myself. I still can't believe it. It's not only that I think about it all the time, it's also that I care how I looked and what others think of me now. I try not to care too much anymore about what others think of me but this one keeps bugging me and I could slap myself. I could hide under a blanket and stay there for years, but I guess that will not help. Even though it's out and the one concerned doesn't mind and keeps telling me it was ok., I don't think it was and would love to turn back time and react differently. I am not writing this because I want others to feel sorry for me or whatever, no, it helps me to sort things out and get it off my chest so I don't have to walk around all the time like a crazy person with sad eyes and in a low spirit...I already feel a little better, now that I wrote it down. And great friends help me even though they don't really ask what's wrong but just them being there and distracting me from thinking about it all the time helps...