The variant I know is:
Even this will pass away.
For disasters:
Nothing is ever as good or as bad as it initially seems; or Nobody died.
For impossible tasks:
You know how you eat an elephant?
If all else fails:
Let's do it.
Regarding the last, it has a double meaning. Others may think I mean, Let's get on with this with fortitude. I do mean that; but these were also the last words of Gary Gilmore before he was executed.
Of course, mantras are great way to relax and keep calm. But sometimes I need more powerful help and I use a dropperful of CBD oil. Yep, the CBD industry is new, unregulated, and has been referred to as "the wild west", but after reading some interesting studies at
https://cbdhealthyline.com I'm sure I've found the best decision for my short-terms sleep problems.