Awful.
If it helps — and I know you know this — this kind of behavior is a reflection on the insecurities of the senders, rather than of the quality of our civil discourse. Tens of thousands of people heard what you had to say, and valued it enough to pay attention. That a handful of assholes felt the need to diminish you as a way of elevating themselves is sad, but far from the norm.
Still, as you say, you shouldn’t have to put up with it. I’m sorry you did, thanks for sharing this experience.