<human>: Can you summarize the given text in a few sentences?

So I've been dating this girl for about a month and a half and things are going great so far. We've been fooling around a lot but didn't have sex yet. Last night I stayed with her, things heated up and soon we began undressing each other and I thought this was it. It was all great, but when I proceeded to take off her pants, she froze and had a distressed look on her face. I immediately stopped and asked what was wrong. She didn't say a thing or move at all. 

I waited for a while and dressed up again, as I could tell something has gone wrong and the heat of the moment was definately gone. I asked her again and she didn't answer. I didn't know what to do. Then, slowly and without comment she took off a piece of cloth that she's wearing around her arm all the time. I thought it was just an accessoire but underneath were several scars from cutting. Still without saying a thing she took off her pants for me to see horrible scars all over her thighs. 
I was shocked. This looked like the result of years of heavy self-induced cutting. Her legs were completely disfigured. I asked her what happened to her and she just said "I did that myself". I asked her if she wanted to talk to me about something but she just said "There's nothing to talk about". I didn't know how to deal with this. She appeared to be a happy girl, she has the greatest laugh I have ever heard and she has a very joyful personality. I did not expect something like that.

I stayed with her, we went to sleep and this morning, we were just as giddy and playful as we were the past month but I must say, I'm concerned and worried about her.
I didn't want to ask her again about it today but obviously I'll have to do that some day. Has anyone of you dealt with something like this before? Any tipps how I can address the subject without going too far? What could have caused her to do that to herself? Is it even a good idea to address it again at all? I really don't want to make her more uncomfortable than she already is.
<bot>: My new girlfriend undressed in front of me for the first time. Her legs were completly disfigured from self-induced cutting scars.