Would you be as angry if a mentally impaired homeless person on a street in your town had said the same thing to you?
Perhaps reframing the situation in those terms will help with the anger. Criticism from sane people stings. Criticism from crazy people is just craziness talking.
I'm sorry you got whacked when you were in a good space to start working on yourself. Yes, it is amazing how a jerk can throw a person totally out off track.
Keep working you though, that's the whole point. Remember to stay focussed on YOUR goals, and not what *anyone* else thinks of them.