@Macha The only real advice I've got may or may not be helpful. I just know it's what often helps me when the pressure overwhelms. (I emotionally process things 'properly' somewhat slowly, and that's hard when there's pressure and stress, especially when the pressure and stress are compounding. It's hard to not just spiral into dwelling on the bad/misery/impending doom once the emotional processing door is flung open as 'what to focus on'. This helps buy me time, and omfg that helps.)
I try to force a sort of 'mental break from the problem'. Often enough, this is some craft project or another. (Stress: that time when there are 20 different projects started in totally different media all over my studio/office; the struggle is real.)
It's not 'pick up something previously started and work on finishing it', though I know some people that works for brilliantly. (Sense of 'solved an unfinished problem' accomplishment, not to be underestimated ever. Even if the project isn't something you consciously consider 'a problem' -- most of us don't -- it's the same feel.)
I'll look for something I already know how to do reliably well, even if I haven't done it forever, and pick up something with two key factors: a new element in it to learn (keep it interesting, present myself with a relatively minor and conquerable challenge), and small enough to reasonably complete without it becoming a dramatic slog. (I am super bad at the last half there, like... so bad. Hilariously fail bad. Still, it is an important thing to consider.)
Shift focus to working on that as much as you feasibly can without shirking whatever RL you do need to manage. Learning the new element will absolutely help keep your mind less inclined to wander than simply revisiting something you already know well without it. And, yep, the new thing should be relatively minor: if you pick a whole new medium(1) you run the risk of it not clicking at all and then the bad feels crawl in right when they're least welcome.
While it's good to pick something you can reasonably finish for accomplishment factor, don't beat yourself up if you leave it hanging. The project isn't really the point. It's there to create mental breathing room for you, and if it pulls that off, it did its job.
- Medium can be literally anything here. Paint, draw, sew, write, compose poems, sing, dance, code... it really can be pretty much anything, provided that thing is not more stress than enjoyment for you on any given day.