Number one, keep your mind busy. A person's mind starts overthinking when it lacks direction. An idle mind always creates problems. So, create a routine: what to do in the morning, what to finish during the day, and what to review at night. Don't sit idle. The day the mind gets proper direction, it stops creating unnecessary thoughts. Number two, write down the problem. The mind keeps repeating thoughts because it thinks you'll forget. For this, pick up a piece of paper and a pen and start writing down whatever is going on in your mind, because this brings clarity to what the problem is and what its solution could be. Number three, the 5-minute action rule. You'll keep thinking until you start something. As soon as you take even a small action, clarity begins to emerge. If you're unable to make a decision, spend five minutes researching whether it's the right thing to do or not. If you're afraid of something, take one small step toward it. If you have a pending task, just start it in five minutes. Take action for instant relief.