As already advised, avoid responding more than once to a comment as that could spiral into argument, name calling etc. as we see celebrities do on Instagram daily. Several celebrities tend to forget that if they are to become role models, they must learn to ignore certain comments left on their Instagram photos by fans. But they don’t know this and let anger get the best of them.
If someone comments on your blog and you deem the comment abusive, you do not need to respond to the person, simply use your super power to delete comment. This is why you must have the privileges to moderate the comment section in whatever blogging platform you use.
Fans or readers are allowed to fight with one another in the comment section as we find on YouTube videos all the time, but not the OP. Your duty is to moderate or simply ignore insulting comments that target you directly.