Whay i do to this girl good or no?

I see a girl in my university and we became friends. We know each others only two weeks. When she dont talk to me i miss her and i feel Jealous when a man talk to her. We don't chat everyday. Once a day i decides to tell her that i like her she said that we are just a friends then i said her that we can't talk with each others anymore. In the university when i see her i don't say hey to her. She message me why you are like that i don't say not to talk to each others, i reply this is better for me. But now i miss her very much and i want to talk to her but I can't because i can't be her friend. What i do?😭