I thought I was starting to understand women.?

Up until two days ago I was dating this woman who absolutely loved spending time with me and likewise. She is diagnosed with social anxiety and has attacks when around large groups of people. She told me that I made that go away for her. We would just lay on my bed sometimes and she would tell me how awesome I am and all terms endeared. Two days ago I didn't get a text or call from her all day so I knew something was wrong. Sure enough I get a call from her and she dumps me flat on my face. I asked her "What in the hell happened?" She simply told me that something doesn't feel right and that she gets incredibly nervous around me and her stomach would tighten up. I weighed all the possibilities so I was ready to hear anything. So what I'm getting at are two simple questions: If you are a woman and understand your own , please tell me, is this normal? Why would she be so nervous around me if I make her day so well?