What did i do wrong here please tell me?

Sorry that you are feeling awful but it sounds like she was never really in to you. Sometimes girls really like the attention they get from guys so they are nice in return to them, but then they start to feel annoyed so they pull back. You need to stop thinking about her and realize there are plenty of other girls out there for you, she is just not the one. Hang in there and whatever you do don't text or call her again.