Here's another quote from Lauren Winner's Still (in which she quotes St. Francis de Sales):
Francis de Sales, a seventeenth-century priest and writer, addressed anxiety in his Introduction to the Devout Life: “Unresting anxiety is the greatest evil which can happen to the soul, sin only excepted.” The anxious heart, in its flailings, loses its hold on whatever graces God has bestowed upon it, and is sapped of the strength “to resist the temptations of the Evil One, who is all the more ready to fish . . . in troubled waters.” De Sales’s antidote to anxiety is twofold, half positive, half negative: do pray, and do not do anything that might actually address the object of your anxiety (do not get online and check your bank balance; the action, far from steadying you, will just make you more frantic). “When you are conscious that you are growing anxious, commend yourself to God, and resolve steadfastly not to take any steps whatever to obtain the result you desire, until your disturbed state of mind is altogether quieted.”
The bold and underline are my own emphases. That's a very interesting approach -- counterintuitive.