I really screwed up with this girl....?

So, Me and this girl are VERY close, on like the verge of dating...But she brought up that shes not over her ex completely and needs to end it with him first, but she still hangs out with him which of course makes me jelous, so I ask her whats up, and she said shes torn between me and her ex......well that weekend we went to a fraternity and i got drunk but she didnt go so she was fine....then that night I lied and texted her that I kissed another girl to make her jelous....well it of couse back fire....now she pissed at me and wont talk....and i think i ruined it with her...Anyone have any ideas of what I can do? I said sorry alot...but shes still pissed...