My timidness is ruining my sexual relationship with bf...helppp?

sexually,and with communication. due to past events, my parents and him do not currently have a good relationship status with each other. since then..i have become a veryyy timid person and nervous and paranoid about everyyything. about becoming intimate with him, about what my parents think about me being with him, just everything... today when i turned down being intimate, he told me he feels like im not attracted to him anymore... i feel awful. i dont know why im like this.... almost every date ends in a fight because of my timidness. he says its because my parents don't let me make my own decisions and still treat me like a child. (we're 19 and have been together over 2.5 years). why am i like this what do i do =/