There are many reasons why people tend to overthink sometimes but with other it's just natural ,its their natural trait . Like you yourself you say you overthink everytime right?
One of the ways which you can use to stop or minimize overthinking is to meditate , by this I mean just give yourself some time during the day to just sit back and kind of relax your mind and have an overlook of the day in general . Ask yourself questions based on your behaviors for the day , if this method does not work , you can also try speaking to someon you trust either on a professional level or personal level . Engaging with people helps in most cases because you will figure out that you are not the only one going through that phase or stage , relatable stories will bring you closer to change and finding the best out of the worst .
Another thing is to pray, I know some people do not pay attention to this process because they feel like it's not determined that it will help whereas it actually does . Hanging around with people most times also decreases overthink tactics, the most you spend time with other people, the less overthinking takes place. Try to eat the necessary food or nutrients to help boost your appetite, eat healthy meals and more water ,that way you will be relaxed. Exercising also helps relieve stress and anxiety in most cases, when exercising, your focus is shifted.