All right I'm new with this and in need of some dire help

My girl and I broke up about 3 weeks ago and I'm having a hard time with it. All my friends we happy that she broke up with me cause they thought I wasn't it. But I think differently. I still think I have a chance to get back with her. She broke up with me cause she thought that I didn't trust her and didn't want to fight with me anymore... a week ago I went to see her to grab some of my stuff that I had left there and I bought her flowers and chocolates, I wrote her 2 and a half pages what I love about her and I wrote her a poem.. when I gave her the stuff and read her the poem she cried so I thought she still cared for me and now I'm talking to her and she says I should move on.. I don't want to and I still think I can get her back... what do I do?