I told my wife flat out to not talk to me about news or politics at all unless it was good news. It took a few weeks to get it to sink in, but she's stopped. I do keep up in small doses so I'm not completely shut off, but I get headlines a couple of times a week, not dozens daily. Set a boundary and either she respects it or you tell her it's time to move on.

I got involved with my hyper-local community. Like 3 blocks around my house. I walk my goats almost everyday and make sure to chat to all my neighbors. I tell and share good news with them; recipes, gardening, weather, Halloween plans, whatever. If they start in with doom shit, I just gently redirect them. "Yeah, I saw that but dude, I found a place down the street that has the best cookies." Again, it took a bit but they've started to get it. We don't have to focus on the shit. We can be aware of it but it doesn't have to be central to everything. One neighbor and I are going to start a block party movie night. I do dumb thing while walking too. Pick up trash, straighten other people's yard signs, move trash/recycling cans back to the yard side when empty. Little shit that just makes other peoples lives a tiny bit better. That stuff is contagious too.

Another thing that's helped is my core friend group. We were already a bunch of nerds, but now we have like 3 rpg games going. Not all of them are regular, but it's a way to tune out without shutting down. There is a spoken agreement that we keep real life shit out of our sessions and they're just for unwinding and living a fantasy for a bit.