@Recccerin I might sound harsh and mean but gurlll do you even have the right to regret? you literally pushed him off the stairs consciously, he could've died, place yourself in his shoes and think what you might've felt if that same thing happened to you, someone you like/are nice to is rude to you and pushes you off the stairs to the point of needing stitches. the only acceptable apology he might accept would probably be a simple and sincere one either said but best if first given a written one though I am unsure if you'll be forgiven by him but after what you've done this is the least you can do to beg for forgiveness .