Love hurts...Need suggestion

I was dating a girl, she is really beautiful, cute, she is just amazing. Yesterday i was taking to her, the unsual stuff, she asked me about my ex and the extent of our involvement. I told her that we were involve till the last phase of love(s*x). She stopped, she replied she can't be with me. I was shocked. I don't know how to react, how to convince her, do i convince her or not? I am really in love with her. I can't control my emotions idk what to do.