How do I make things better with her?

Well, the things is that we were best friends before. Then I knew that she liked me and I also like her so I got into a romantic relationship with her and made it official without telling her, because she should be happy and suprised. But instead when she learnt that she's actually in a relationship with me then she scolded me and blocked me everywhere and since then she won't talk to me. It has been 7 months and yet now I don't understand why she rejected me. Instead, I want her now more badly. She's here actually and I want to hear her out. I can't leave her, I have been crushing on her for 3 years. Like I literally see her in my dreams every night, it has been like that since three years. I followed her and posted few opinions under her questions and mytakes. She is a good writer and pianist and I guess she's a bit well known here maybe you know how wise she is. How do I make things better with her?

How do I make things better with her?
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