The worst mistake during my stay at ISM

You don't know why it happened once it has happened... only thing you wish is it should not have happened.
Today I made worst mistake while being at ISM. It was sudden adrenalin rush and I strangled and pushed him, even though I never intended to hurt him, he started bleeding.
But I couldn't have controlled either. Throughout my life I have lived by a rule to never talk (or ignore) to those people with whom I can get into problems( read "fight"). I take this decision only when I exhaust all methods to get along that person. Its better to leave a shimmer of hope than killing it all together by having a bad fight.
But this was not the case with this boy. He could keep from interrupting into my corner. Today was it and on a whit of provocation it came out.
Sorry for that... I cannot say sorry to him and I know I shouldn't , I am saying sorry to myself