Dear sir, Your problem is indeed troublesome. This problem of unstoppable thoughts can be a part of multiple disorders. In some cases, the treatment is through medicines and in some through psychotherapy and thought stopping/controlling methods. For correct treatment, it is important that you meet a psychiatrist and get yourself diagnosed. After this, a psychologist may intervene for non-drug treatment. Regards!

Was there anything that you was not happy about ?! Are worried about your past failures and not able to prove after that?! I think know you need to first five days the answer for these questions and you will know by yourself How to handle the problems which you have mentioned !

First thing you have to consult a psychiatrist. Detailed evaluation is required.if required some medications may be required. You also need counselling.