Ripping ..

So the other night me and my fiancé dtd, and he tore me. Wth. This has never happened .. Now I have tiny little tears down there IN there.. Ugh:( have to wear ice pads and wash it every time I go wee.. The doctor couldn't even tell me why I would tear if it's never happened before .. Anyone have any guesses as to why? 
Please no rude comments, I'm in a lot of pain and I'm just curious as to why this would happen.