How do I stop being extremely over-sensitive? Please give me your advice.?

Have you considered seeing a therapist? You might not be depressed, but it sounds like this is really affecting your life. They can teach you some coping strategies and maybe help you get to the root cause of why these things are bothering you so much. Anyway, I hope things work out for you; I know how embaring it can be when you overreact to someone being rude. One time in high school I almost started crying in front of my teacher when he was extremely rude about not letting me turn in a paper late.