The pictured sign says it all. That's what I do!
I then do something that pleases me eg listen to favourite music, watch a fav tv show, watch a fav movie, have something I love to eat, even if I have to go to a shop to get it, a hot cuppa, followed by a nice glass of quality Oz red wine!
Then to sleep!
I laugh at myself and say thank goodness this does not happen too often! Maybe not do anything too serious just in case it goes bad and wait until I am back to "normal". I do like some of your suggestions like treating oneself, that always makes me fee better yay!
Those days typically involve blood. Mine. I am a klutz. If I hurt myself more than twice in a morning, I give up, make a cup of tea, sit on my bed and read. Usually with a bandaged finger or two or a mangled toe. LOL
If I am having a bad day I step away from important jobs and work on something simple. If I cannot walk away I take some deep breaths and try to sort things out.
If I am at home I have a nap and see how I am when I am well rested. On a very bad day , I pull the blankets over my head and stay put so I avoid further harm.