Halanna

This just seems weird to me. For her to come right out and say this then to maintain contact and refuse to talk about it - my instincts say something is off.

My first thought is she has obviously been to a gyno after all these years, any problem she had would have has been solved by now.

Unless you are the size of a baseball bat, and you only had vaginal sex, there are no places other than the usual for there to be any tearing. In normal teenage sex, as you described, you could not have done any long term damage to any part of her. Now if you used toys or unconvential impalements then maybe, but not to the degree she has stroked your guilt to.

So, I move to my second thought. You say you have a "close" relationship. Do you answer the phone every time she calls? Do you help her if she makes a request? Do you feel like you need to "be there for her"? Is your confusion and guilt making you more available to her than you would be under other circumstances? If the answer to any of these is yes, then her goal is accomplished.

If I were you I would say, "Look, I need to understand what you are talking about. What does your doctor say? What exactly happened because I don't understand."

If she continues to refuse, then look for the reasons she is trying to keep you in her life. Not for how you physically hurt her.