We'll give you three ways to help yourself. The first option is meditation. Don't look for anything mystical or esoteric in meditation. It is a simple method, but a very effective way to control your thoughts and emotions. The only condition is that you must meditate regularly every day.
Just sit on the edge of a chair, pull your body up towards the sky - behind the Bai Hui point (the acupuncture point on the top of your head). As if you were a puppet and pulled upwards by a string. This will straighten the spine. And then all you have to do is watch your breathing. Inhale, exhale... Inhale, exhale... Inhale, exhale... Over and over again.

The thoughts will keep coming, that's normal. But you imagine them as bubbles, observe them and let them float around. Or push them away. But don't evaluate them, don't analyze them. Just observe them and let them float by. They don't concern you. Yes, it's hard at first, but try it gradually. Start with a short meditation for five minutes. And each day, extend the time until you can last 20 minutes. That's enough. Just remember to meditate every day. You'll soon see how your thoughts and emotions will stop controlling you and you'll control them.

Another way to calm the mind is regular exercise and sport. Ideally, movement that engages your mind (e.g. team sports). It must not, however, be too exhausting. Any more loss of energy and blood, on the other hand, can make overthinking worse. Fast walking or Nordic walking is ideal. And feel free to combine walking with meditation. There is a form of meditation called "walking meditation". It's harder than sitting, but after a while you learn this too.

The third option is Chinese herbs - specifically the herbal blend Gui Pi Wan. You can find it at www.YaoMedica.cz under the name Anchored Idea. It is an old herbal recipe that harmonizes the relationship between the Heart and the Spleen. That is, the organs whose imbalance causes compulsive thinking. It's also called the "student blend". Prolonged sitting over books and computers weakens the Spleen organ. Constant studying, thinking and gazing depletes the blood of the Heart, which, moreover, does not even form sufficiently because the Spleen is weaker and weaker. When blood and Qi are really low, thinking ceases to be effective and turns into mere ruminating. Fatigue and sleep disturbances appear. As the Spleen's Qi (and its ability to hold blood in the blood vessels) weakens further, bruising and various types of bleeding occur. Of course, this does not only affect students, but all mentally working people.

So if you have trouble thinking, use the Anchored Idea tincture. It should be taken for at least 2-3 months. But as always, a lot depends on the specific condition.