I never thought that knowledge bring so much headache.

I was thinking about what i learned, and I had the conclusion that I learned a lot words and expressions.
But this knowledge brought me headache and made me feel so dumb. I know that I will be better, but right now I just want close my eyes and open when I know how say every word and know how express my thoughts and opinions .. I'm so upset with myself, why I have to be so shy ?! It's killing me.