Worry is a complete circle of inefficient thought whirling about a pivot of fear. To avoid it, consider whether the problem in hand is your business. If it is not, turn to something that is. If it is your business, decide if it is your business now. If so, decide what is best to be done about it. If you know, get busy. If you don't know, find out promptly. Do these things; then rest your case on the determination that, no matter how hard things may turn out to be, you will amek the best of them - and more than that no man can do.