I'm afraid to speak out because of my upbringing?

Ever since I was a little kid my parents thought everything I did or said were idiotic. I would be hushed. Little funny mistakes I’ve done were treated like the end of the world. I was even beaten up on multiple occasions because of small things. In dinner tables I were always quiet. When I spoke I was talked on by someone else in my family and ignored most of the time. I was very quiet in classrooms. I believe that anything I say would be idiotic and looked down on, so I don’t speak. I wanted to do many things but I’m afraid of doing them because I think I’ll fail anyway. I don’t know what to do at this point as I am in my twenties and still my comments are being looked down on by my parents and siblings. If I share with them something I’ve said or done against a behavior I disagree with, my sister says I am an idiot and that I should have better things to do.

At this point I need your opinion on this. Its hard for me to speak out at all. I regret everything I’ve said or done after awhile because, well It was just idiotic wasn’t it?

I want to do so much in this world, I always have. I want to be the change I want to see in the world. However in the back of my mind I am an idiot, a loser, a failure, and anything I do will fail because its stupid. Please help me. I really need help. Do I just go for it and fight with how I was raised every single day? How do I stop fighting with it and win? Because I hate the thought of being a failure all the time which is on the back of my mind in everything I do or attempt to do. I don’t wanna live like this if its gonna stay there. Can I forget those many years of my life?