I've learned over the years that saying, "do nothing, just sit there, et cetera," it's not actually the best way to take somebody who's in a high pressure, high-emotional state and deal with that.
If you have the anxiety, you need to put it somewhere and channel it towards something. Instead of saying like, "just sit on your hands and do nothing." The answer is, "we are gonna take this and we are gonna channel it towards things that we know are definitely positive for us."
Are there any investments that, if the market as a whole is down, you're actually quite happy to get out of it now? Maybe it was a high-fee investment that you got into years ago and hasn't really been doing that well lately; maybe it's something that you inherited; maybe there is a rebalancing between accounts, between IRAs and taxable accounts that would be good to check on now.
There's a whole list of these things that you can do. The important insight here is: don't deny your humanity. Don't say like, "No, I'm not gonna do anything." I'm gonna just stoically stare at all the red on the screen and say, "this too shall pass, and it's totally fine."
No, we're gonna say like, "when the market goes down, what is it a good opportunity to do?" And let's do them; let's take action. Let's fill up our to-do list with things that we know are mitigated goods in this scenario. And having those things to do, having that sense of like, I've got an outlet for this anxiety that's gonna allow me to get some stuff done is very positive.