These are tips I can give when dealing with an hater.
PAIN: People sometimes let off steam because they have problems in their lives, and they may have nothing to do with you.
REFLECTION: What a hater says is a reflection of himself and is not about you.
Who feels good does not need to drag the others down.
I still remember a guy calling me "gay" as an insult in high school, and he secretly was. The worst thing about this is that homosexuality should be respected and not used as an insult. I am happy that finally, he found peace
IGNORE: You want to respond to that negative comment, but don't do it. Of course, if that is a threat, then you can report this to a lawyer
BLOCK: A simple thing you can do: just block him/her. Remember to take some screenshots, and if needed report this to the platform
RESPECT: Yes, you should respect your hater, even if he/she doesn't deserve that. It is important because by doing this, you demonstrate that you are in control of your emotions and that you are not let down by negativity, which is what he/she wants.
SUPPORTERS: Ask for help. A real or virtual friend can help you in this situation, and the hater is gonna feel more isolated if there is a bunch of people protecting you from his/her attacks
BE YOURSELF: Don't change who you are because someone stopped you with a bad comment. Be yourself and keep going.
I hope I have been of help to you my friend.
You are awesome!