the stigma

why is there such a stigma associated with mental illness?
I am afraid to tell people about me , because of it. I can't tell people when there is something wrong, as I fear they will not understand , and come to their own incorrect conclusions. I believe everyone has a right to individuality, and if we are happy, we should be satisfied. But why do I feel like I have to hide myself just to please everyone? Sometimes I feel that even my family are ashamed of me. I can understand why, but why are they? It is very complicated. I want to change myself and act like nothing is wrong, but on the otherhand if I accept things are wrong then I can maybe I can heal. I also wonder if it is just me trying to accept that I am sick. It is a hard thing to come to terms with.