I read this book by Joyce Maynard, an author who, when she was young, had a relationship with J.D. Salinger, a famous, much older author. She wrote how he couldn't penetrate her, and how she felt so awful for so long because of that. And yet, after their relationship, she eventually found someone who she could have pain-free sex with. She finally concluded that much as she consciously thought that she wanted to be with that first man, something unconscious was adamantly opposed. I'm not saying this is what is going on with you, but at sixteen years of age, many women don't yet know themselves. There is brain wisdom and there is body wisdom; sometimes you should trust your body and wait.