I don't know if this helps at all, but:
I've found myself reaching peaks. And whenever I reach a new PR, I am split between playing another game and not. What if I win and get an even higher PR?! ORRRR, what if I start losing and all my hard work (of scamming other players out of wins on time) starts to regress? Once I stop playing for that day, I find myself not playing blitz (which I normally play as) but bullet. Because bullet is more volatile for your rating and doesn't matter as much to me as much as my blitz rating. When I start trading bullet for blitz games, once I start to try and get back into blitz, my rating plummets (usually no more than about 100 points), but after several days of consistent play, it will usually start to come back up.
I also have spent several hours putting into tactics, lessons, and learning end games, or this or that. I'm kind of burnt out on it as well. I'd suggest during a regular break in your day, be it breakfast, lunch, or dinner, to just watch a chess video (I prefer "Chess Network" on YouTube). While I am lifting, I have a tendency to do puzzle rush (because I'd rather not lose rating by playing a game) during my rests to catch my breath. I think those small things help to keep you sharp. Also, during these periods, study the things that are interesting. I started studying the queen vs. rook endgame, solely because I thought it was interesting, not out of practicality, but those things usually become practical because it's a new idea.
At the end of the day, it's just a game. I've had my fair share of unsportsmanlike conduct as well as everyone else. To some degree, those of use who play it, we play it, because we love it. Though I like to analyze the games I win on chess.com, I also do the ones I lose (though I'm usually pretty irritated during that time). You know yourself best. If you need to stop playing during those moments do. I will get irritated at myself, and then play another one, just searching for the high of a win to overcome my own insecurities. Part of the point of this paragraph, is to point out it truly is an empty endeavor. Lets go to the top... what else is there for Magnus Carlsen to do? Ignoring Magnus's issue, practically speaking, is there any chance of us likely achieving Magnus's level? Doesn't that mean that there is always someone better than us? Chess has to be wrapped up in something else for you to not get down. My friend at my chess club says that he plays little kids to get a few wins in for the night before he goes home.
Unfortunately, in a godless world, you run into that issue of all endeavors being vain. But in a God (ful?) world, all things have a purpose.
Lately blitz goes really bad, for the last few years my rating used to hoover between 1900 and 2000 mostly, but last ten days my rating went down from about 1970 to 1730. I never had such a big downswing and its pretty disheartening, I just can't win anymore. I also think I just play worse.
Today I only played one game, and I badly lost again, against a player with a rating i would normally almost always win from. I don't even dare to play a second game anymore, also feel too disgusted to play a second game too.
I had downswings before, but not this bad or long, my FIDE rating is 1840, but I don't even dare to play OTB anymore in FIDE rated events because I am sure I will ruin my FIDE rating with the level of chess I show lately in online chess.
How do you guys cope with it. Also makes me want to quit chess, as when this happens chess seems such a empty endeavor anyway. Yeah I could study more again, but must I put in a bunch of study not to improve over my old level, but just to get back to my old level, nah that doesn;t sound pleasing.