When i did a mistake, i have a sense of guilt that is not normal, let say excessive. i am afraid, can allow mental or psychological damage.

We all make mistakes: Mistakes are part of being human, we all make mistakes. If you learn from mistakes they become assets. Learning to apologize when we make a mistake that hurts another person is also an important skill we all need. Learn to embrace your mistakes rather than worry or feel guilty. Do something about them and they will not leave you guilt ridden. Hope this helps!

Shame/guilt: Shame/guilt is just about the darkest emotion people can face. It presupposes that there's an audience to our alleged wrongdoings, and that devastating judgement will be passed. Something to remember is that everyone has something they feel ashamed about; it's inescapable. Find a reputable psychotherapist to speak with. Getting it off one's chest in a safe, nonjudgmental place is the first step.