I go for walks, play some silly video games like Stardew Valley, read a little bit, maybe have a horror movie marathon, and I do that for a day until I feel like it's the right time to go back to chess. But when I have bad days where I can't play well or do puzzles, I have a chess-free day, and it seems to help.
The last few days in fact I've done just that. Today was a zombie day full of George Romero's movies, played some GTA 5, and just relaxed, not thinking about chess at all. I know tomorrow I'll be ready to go back to it.
Like the title says, how do I deal with chess burn out. A few weeks ago my elo was climbing I was playing games, studying, doing puzzles. Now it's just dropped I haven't changed anything. It's like my brain just refuses to play. My past like 10 games were terrible. It's like I've completely lost my ability to think.