Overthinking habits. Rid of this habit?

You might be having challenges with expectation management that keeps you imagining or fantasising about future. This is absolutely normal. Continue doing this but before that explore what you want to do in life  (personal,  career etc ), prepare a plan to set your goals and then imagine or fantasise only positive and success results.  If you think/visualise positive you will attract positive energy or it will be otherwise. You can do nothing about your past as there is no reverse gear,  but you can fulfil things in present and future that you couldn't achieve in the past. Consult a Counselling Psychologist in your city who can help you set goals, working on priorities and take appropriate decisions to move ahead.