Being able to speak up in front of friends but not able to in front of my mother.

Few minutes ago I wasn’t able to speak up when my mother asked to ask the worker for some simple food, and I froze. My mother pissed walked out and told me “when you’re with your friends I’ll tell them you can speak infront of them but not infront of me”. She’s right, I can speak up for myself infornt of my firends but when I’m with my mother I can’t. What can I do to stop this? Is there something wrong with me?