Hello Friend, Good that you are seeking a help here. Yes it happens. One negative incident or negative person can change or influence your mind and thoughts. You are experiencing the same.
Be positive. There are ways to recover from such negativity and stress.
As a first step, You may need a guidance of counseling support to figure out the real root cause that is triggering such emotions and suitable solutions that help you overcome.
Next Steps
Consult a psychologists directly or reach out to me online through Practo app for further evaluation and recommendation.
You will be alright soon.