welcome to healthcare magic
As u have said that any adverse event brings anxiety
as well as negative thoughts and you can't control it (right from childhood) ..... so it might be you are suffering from some sort of Anxiety disorder.
But don't worry ..... your problem can be solved easily as there are many drugs to control these kind of thoughts.
U should consult a psychiatrist
as soon as possible and i assure you, you will be alright after treatment ....... however, before that u try some relaxation exercises like deep breathing, yoga
If you can give some more details about your problem..(like what kind of adverse event brings anxiety?).. i can guide you better...
Hope it helps
Wish you good luck