How do you not over think and stop worrying so much?

Honestly, this is a question i got to answer for myself every day... But in my experience with this struggle, I have somewhat managed to deal with stressful thoughts, bad moods, worrying about things too much and just thinking overall. I have done so by sometimes just taking some time for myself to relax and escape the reality. We all need that from time to time. I would ask someone out, call a friend, chat with people who can make me laugh, I would pick up a new book or watch a movie, or, even, talk to someone who would reassure me that my overthinking is only that — an overthinking and worries that do not belong in my life and that i need to overcome.

Acknowledge what you are thinking, and write it down. Sometimes our thoughts can overwhelm us. The trick is not to fight those thoughts, but to let them be and let them exist. Let yourself worry, acknowledge, and soon they'll fly away. Keep a daily journal and write down thoughts that are bothering you. This puts the thoughts down in a place away from your head. Daily mindfulness exercises can give you a healthy response to thoughts. It's a skill to learn about how to let your thoughts float away. If it's a particular thing you overthink about, it may just be a sign you need to organize things. If grades worry, try to set aside more time to worry about school and get that work done.

What I find that can be useful is grounding myself in the present moment. Giving a moment for my thoughts to flow without me associating or identifying with them. When worry thoughts or over thinking of anything happen, I try to catch myself in the process and actively acknowledge that this is me doing this, then taking that moment. Alternatively, breathing exercises are helpful. Rationalising thoughts I find helpful although a skill that needs to be practiced to learn. I also find dropping into my body sensations and feeling what I'm experiencing at that time can be useful. Ultimately its arming yourself with a tool set to deal with these aspects, there's no one thing fixes all for me. I try to alternate methods to suit my state at the time.

First thing to realise is that you are not your thoughts. You are awareness behind those thoughts. Don't try to control thoughts. Thoughts will come and go. They are like clouds. Where as you are the sky. Just allow it to pass by. Don't focus much on them. When u feel losing in thoughts try to bring awareness to present moment. You can bring awareness to present moment by focusing on something neutral like breathing or observing nature or you can focus at a particular place like on candle or specific point on wall. Music too helps shifting your focus. Walking, writing, painting whatever keeps u in present moment will help you.