The best way to stop overthinking is conscious micro action meditation ( laghu jnana kriya).

You can come out of the repetitive thought patterns by witnessing the thinker inside you. Witnessing will give you the state of "no-mind" -the state of deep inner connectedness. Gradually, you move into the state of pure being - the state of pure consciousness.

Meditation is not a task to perform but allowing the thinking engine to take rest. In the restfulness of the thinking engine eternity arises.

Inside mind there are two parts: the controlling mind (ego), and the relaxed but aware mind (self). The controlling mind is the overthinking mind. It is the ego. It tries too much and has many doubts and conflicts. It overthinks and overdoes. It is full with excessive possessiveness and attachments. On the other-hand, the relaxed but aware mind has the natural ability to face and overcome the problems of life with awareness and efficiency.

Overthinking arises when you are disconnected - disconnected from the body, mind, soul, society and the nature.

Overthinking evaporates when you feel connected with your body, mind, breath and the soul.

If you want to conquer overthinking, bring your mind to the present moment and reconnect it with the immediate world.

Overthinking is not a disease; it is due to the underuse of your creative power.

As cow, deer, and goat chew food again and again in endless circles, overthinking creates an endless loop and exhaust energy. Conscious micro meditation (Laghu gayan kriya) can bring you out of the loop.