I slapped him in the face

Let me start off by saying that I feel incredibly bad. He had his head on my arm and then he fking bit me for no reason and I reacted. He’s always doing this and I keep telling him it hurts. He says that bothering people is how he shows his love. I wasn’t looking at him when I did it I just felt the pain and swung. I’ve said sorry so many times but I can tell that I really hurt his feelings. He says that it’s fine but I know it’s not. Idk what to do now