Some days are better for remembering that not all days go as planned. Some days, the best you can do is pick up the pieces and sit there. Or move on. Or hold still. Or try to get one more bit of something semi-nutritious into your child. Or one more minute of quiet for nap-time. Or one more sip of water. One more errand out of the way. One more thing, one more try, one more effort, one more, one more, one more.
Glue something down. Ready when it’s time to work on a piece again.