Not all mother's know the best to their daugther/son

I was really confused why my mom acting like a nerd,strict and so so overprotective to me. I was doing my studies well. I make my grades so good as well as having good performance in school but why is she still have to decide for my future?..she even not let me to decide whom i should be love. I dont have freedom at all. Why isnt she doesnt understand what i felt?..I feel so alone,depressed,and hopeless. I guess i dont have right to be happy?:(..How long will I sacrifice this pain i feel inside.?...I attempt not to jealous to others and attempt not to cry but tears will fall again...:(