Hello Friend, Good that you are seeking a help here. Appreciate you for analyzing the problem and isolating it to negative thoughts. Probably, you need a professional help to further analyze and figure out the actual root cause. You will be surprised to notice how your lifestyle, dietary, environmental etc can are influencing such negative behavior.
Take a counseling support to figure out the reason and also a suitable solution to overcome.
Next Steps
Feel free to reach out to me online through Practo for further detailed evaluation and suitable solutions that you can follow practically to overcome. You will be alright soon.