One of the most helpful things you can do as a writer (or in life) is learn to identify the difference between negative criticism and negativity.  It’s easy to get the two mixed up at times and I suspect that the line between the two varies slightly from person to person.
But in life you will meet people both critical and negative.  You want to surround yourself with critical people – people who will say “I love ya, but you’re wrong”.  They are honest, warm and utterly, utterly brutal.
Negative people, on the other hand, hate everything.  They will default to use of snark (badly), ridicule and belittle.  They are utterly exhausting to be around.  More often than not (and as I go through life I’m finding it’s a lot more often than I once thought) they tried their hand at something, got knocked back, and never got back up.  They blame their failure on the world around them instead of the simple fact that they never got back up, worked hard and tried again.
I don’t believe that as an artist you should surround yourself with sycophants.  I’ve seen first hand what that does to some people in the entertainment industry, how they become so detached from reality that any criticism is automatically seen as negativity.
But, as harsh as it might sound, I do believe you should cut negative people from your life.  They are like quicksand, dragging you down with them.  I’ve had to do that several times in my life (the last time a few years back) and it’s never a nice thing to do as it leaves you feeling like a terrible person.  Given half a chance they’ll make their failures seem like your problem.  It’s not worth trying to reason with them, just cut them and move on.
The same should be said for internet and social media kerfuddles.  If it’s critical, it’s sometimes worth getting involved.  If it’s all just negativity, even if that negativity is directed at something you oppose, just walk away.
Honestly, you’ll feel better for it.