Overthinking means thinking about something for too long and making it into a problem.... problem because generally, overthinking happens around negative thoughts, negative emotions, negative imaginations and negative assumptions. Mind is indulged into multiple things that don’t help you think positively. And these negatives produce nothing meaningful; they only lead to worries and anxiety, which harm our mental being, then physical being, and our spiritual well-being too.

Negativity gives unhappiness and positivity gives happiness.
Negativity will waste your time in useless matters, will create entanglements, will not let you experience happiness. It will not let you come out of things that don’t help you think positively. So, rather than wasting time in destroying the negativity, remain positive in worldly life - negativity will break off automatically.
Any positive line is towards God i.e. the divine, and any negative line is towards devil i,.e. the evil. That is why Gnani Purush Dadashri, founder of Akram Vignan, says: ‘Remain positive in worldly interactions, do not become negative.’ If you remain positive, then any worldly obstacles will not affect you!

So, let’s see what we can keep ourselves occupied in, to keep our mind off things that do not help us think positively...
Keep an eye on your thoughts. When the thoughts pass a certain stage, and are about to take a negative spin, try to stop them there and then by say to your mind, ‘show me something else.’

Do something different. For instance, go for a walk, exercise, have a small chit-chat with close ones.
Beware of the company you keep. Surround yourself with positive people who bring out the best in you and help you progress.

Counterbalance your thoughts. Instead of fighting the negative, replace those thoughts with the positive ones. Your intellect will keep engaging you in the negative thinking; but you keep up with your task of bringing out all positives.

Creativity incites positivity. Engage yourself in something creative and constructive. Decide to do so and you’ll soon meet the opportunity too.
Remain in present. One is generally found pondering about the past or worrying about the future. Try to focus on what is before you. It may not seem easy, but engage yourself in the present. Very calmly and in a friendly manner, keep bringing your mind in the present; and you will soon see that your awareness has greatly enhanced.

Recite a mantra of your faith, but in this manner... Close your eyes and for about an hour, repeat the mantra or the God’s name in which you have immense faith, visualising every letter that you say with your closed eyes. Eg. D-A-D-A B-H-A-G-W-A-N N-A A-S-E-E-M J-A-I J-A-I-K-A-R H-O! – if this is the mantra, visualize each letter D... A... D.... A.... This will improve your concentration power and break the link of overthinking on a particular matter. Dada Bhagwan Na Aseem Jai Jaikar Ho itself is an auspicious sentence that has brought a lot of peace to thousands of people during their testing times; so you can even chant that, if you like! And if one hour seems difficult, begin at least with ten minutes.

Ask for forgiveness (pratikraman). This is a very good and effective solution to stop overthinking and move towards positivity. There has to be something negative churning within you, which leads to overthinking. And if this negative is hurtful to some person, you must seek forgiveness from God for that negative. Doing so, not only will the negative break down, but consequently overthinking too will disappear in thin air! Yes, pratikraman is indeed miraculous; try it. The practice of pratikraman will in a big way lessen the effects of the toxic thoughts too. The more you practice this, the greater is the result. Let’s learn how to practice it.

Confess – Dear Lord, I have been hurting the other person through this bad thought since long.
Apologise – I now apologise before you for this mistake.
Resolve – I affirm to not repeat this mistake anymore.
Attain Self-Realization! This is the ultimate solution that comes straight from Gnani, the Enlightened One!!! Know ‘who am I’ and ‘who is overthinking’, and everything will begin to fall in place. Seeing things ‘as is’ resolves any problem from its roots, says Gnani. As long as one has the false belief of ‘I am the owner of the body and name’, one will continue to have negative thoughts. After Self-Realization that, ‘I am a Pure Soul, an abode of eternal bliss. And the other person too is a Pure Soul, an abode of eternal bliss, just like me. We both are one only!’, all the negativities, all the divisive feelings begin to dissipate naturally, automatically.

After Self-Realization, life takes a natural turn on the side of the positive, and as a direct result happiness prevails!
When one attains Self-Realization, the Akram Vignan way, two things happen:
You realise the real Self i.e. the Pure Soul.
You come to know which entity is the doer and how things happen.

The wonder of this Akram Vignan, the spiritual science, is that it is an extraordinary science. It immediately turns a person to the positive side. The Self is towards positive and the intellect is generally towards negative.
Thus, go to Gnani, attain the Self - an abode of eternal happiness, and say goodbye to overthinking - the biggest cause of unhappiness!

To know more: https://www.dadabhagwan.org/path-to-happiness/self-help/positive-thinking/

Author's Bio: 

Ambalal M. Patel was a civil contractor by profession. In June 1958, spontaneous Self-Realization occurred within Ambalal M. Patel. From this point on, Ambalal became a Gnani Purush, and the Lord that manifest within him became known as Dada Bhagwan. A Gnani Purush is One who has realized the Self and is able help others do the same. Param Pujya Dada Bhagwan used to go from town to town and country-to-country to give satsang (spiritual discourse) and impart the knowledge of the Self, as well as knowledge of harmonious worldly interactions to everyone who came to meet him. This spiritual science, known as Akram Vignan, is the step-less path to Self-realization.