As a writer, when you’re successful, you may get trolled. This is one of those instances where being a public figure becomes a problem.
Trolling is done by a single person or a group to provoke, using negative comments. Some people have taken their own lives due to being trolled. It is clearly a grave thing within social media and, quite frankly, disgusting, debased behaviour.
This is bullying if someone demands that someone else behave in a particular way. Mocking someone and making cruel comments is bullying also. Gaslighting is telling an alternative reality, manipulation.
People who do or say or write negative things to others are psychopaths, as the acid test of being a psychopath is empathy. Nobody wants negativity; people wish to receive supportive, positive comments, and the trolls would not like to receive negative comments about themselves.