Wife

I'm not sure I understand what it means to be a wife?
What are your responsibilities?
I think I'm freaking out about getting married. I feel like he expects so much of me. He doesn't allow me to express myself how I always have, he just says that I should soldier up and be extra happy when his happy. So even if I'm dying inside I have to pretend I'm happy just cos his happy? I don't know if I want to marry him but I'm too deep in and there's no turning back now