She said that if we were the same age we would date

I just want to start off saying that I'm a 15 year old guy. Back when in was in grade school I met a girl who I was really close friends with. She was a year older than me so the only time we had together was on the bus. Our grade school only went up to grade 6 so when she went to another grade school for grade 7 we only text talked on msn (remember that thing?). Anyways, we stayed close until the following year when we were at the same school again. We were still bus buddies and stayed in touch over the summers and after school text talking on skype until she graduated grade school. We stayed in touch the summer she graduated and that summer I told her that I had a thing for her. She said that when she was in grade 8 that she liked me to and that if we were the same age we would date. When she was in grade 10 and I was just starting high school we weren't on the same bus anymore. We still text talked on skype. When ever I saw her in the halls at school I always seemed too scared to say anything to her. Later that year of grade 9, I could tell that something was different in our conversations. I had the feeling that she hated me or something. I came right out and asked ''if you don't want to talk anymore just say so and I will leave you alone.'' This was a text that I sent. She responded the next morning and said to ''stay the fu** away from her and leave her the fu** alone.'' I was really surprised because she had never, not once sworn at me, and I have never sworn at her. We still go to the same high school and every time I see her I think of what she said and how much I'd like to be friends with her again. I don't know what to say to her, or when to say it if ever. I would love your feedback with what I should do. Thanks in advance -Nathan