One of the attractions of worrying is that paradoxically it can temporarily make us feel less anxious. When you run a problem over and over in your head it can distract you from your emotions and make you feel like you're accomplishing something. This is an illusion. Worrying and problem-solving are very different things.
Problem-solving has a number of distinct steps, each of which moves you closer to a solution. You begin with a realistic evaluation of the situation and then move to planning the steps required to deal with it. Finally, you put the plan into action.
On the other hand, worrying has little sense of direction. You go round in circles and seldom get as far as a solution. In fact, you could spend a lifetime worrying about potential catastrophes and still be no better prepared to deal with them.
So if a worry pops into your head, get into the habit of questioning whether the problem is real and solvable. Ask yourself, is there an action I can take which will deal this problem? For instance, if you're behind with your work, you can do something about that, right away. Once your start doing something about a problem, you automatically feel less anxious.
On the other hand, if you are worried sick by thoughts about an accident happening to your children, then that's not solvable. There is no action you can take to avoid random events in the future.
Distinguishing between problems that are solvable or unsolvable, real or imaginary/hypothetical can be an important step to achieve relief from anxiety.