I was playing basketball up at my local gym, and this guy asks if he can play with me and some friends, and I quickly got him into the game. He was defending me, and after I had blocked a few of his shots(not trying to brag) as I drove in for a bucket he elbowed me in the face. I told him I knew it was intentional but I was gonna let it slide. After the next shot of his that I blocked, he shoved me against the wall, so I popped him in the mouth. He was dazed for a little while and then said, "Take it easy white boy," and left the gym. After thinking about this for a while, I've began feeling bad about what I did, since I'm in no means a violent person. I've been trying to find him so I could apologize, but haven't seen him since the incident. So, should I feel bad for what I did, or was my self-defense justified?