I am going to give a piece of advice, as I know a lot of my fanbase is a bit younger and this is the first time they've dealt with a situation like this.
When someone is harassing you, or being mean or generally just a bad person. Do not engage with them.
Don't reply to them, don't acknowledge them, don't do anything. Just block them or ignore them.
I know the urge to defend yourself is strong, but these people thrive on attention, they thrive on getting a rise or reaction out of you. The only way they'll stop is ignoring them all together.
I hope you all can take my advice to heart.