C11 to C10 story: My girlfriend left me and now she wants to come back in my life...

Few weeks ago I checked Workday and saw that I was not promoted, while other people here were promoted apparently. Apparently, you could check in your workday whether you were promoted or nah. Anyway, I was disappointed that I was not promoted from C11 to C10 even after working so hard. In my moment of weakness, I confided in my girlfriend. We have been dating for 3 months now. I was in a horrible mood and wanted to let it all out. She decided to break up with me by the end of that week and said that it wouldn't work out between us. It was a very sad moment for me, after not being promoted and then the break up. But FINALLLLYYYYYY!!!! I got promoted from C10 to C11. Apparently, workday method was not true for me. I am very happy that I got promoted. I told my family and friends. Since, me and my girl had recently broken up not many people had known about it so someone must've asked about my promo to her. Now, she's saying that why did I lie to her that I did not get a promo(I did not lie at all) and she wants to get back together and said that she is sorry. What should I do now? I can't resist her anymore. Please help me