help!!

So I told my grandma that I think I have a yeast infection or something because I've been itchy down there and she asked me if I had sex and I lied at first and said no scared of her reaction than she told me to tell her the truth so I did and she's not very happy about it and she's like forcing me to go on the pill but I'm 16, shouldn't I be able to like control if I want to be on the pill?? Me and my boyfriend are protected everytime and she like keeps asking me when I'm getting my next period and things like that. This is why I've been hiding it from her. To avoid all these questions and such. I don't know what to do guys.