One of the wonders of the fediverse is that it doesn’t have all the awful algorithms of Reddit or other social media platforms that are designed to relentlessly attempt to draw you in with increasingly hostile content. That’s not to say there isn’t a lot of negative content out there. There is. But, with Lemmy, or the fediverse more broadly, you have the ability to curate your own feed and an algorithm that will override that doesn’t exist.
I suggest using the “Block” button liberally. I’ve found that works pretty well for me.