Stress and anxiety. This this situation?

I have noticed that some non threatening events are causing immense stress in my body. For example few days back I noticed a road accident which didn't bother me anyway but still I noticed my heart beating . Again one day I took my mother to doctor for routine check up and I created a false notion in my mind that my mother would be severely sick even though she is completely all right. During those time my heart beats fast and a sense of fear working in my mind. And slowly it subsides. I am 100% sure there is nothing with my physical health. How to deal with this this situation? And please provide a solution by which I can definitely overcome this problem . Pls sir/ ma'am provide a solution.pls.