@sand I read somewhere else in my feed a (long) while ago, and it really helped me come to terms with days like that: "You're the toy."
The point (for them) isn't to have you find some thing they want to play with for a while. It's to play _with you_. So you can either play along, and be a toy for a while, or decide you don't have the time/energy/stamina for it, and just refuse. They'll figure out some other way to entertain themselves if you give them long enough.