is one sexual text enough to warrant a harrassment case when I feel she was flirting with me and sending mixed signals and regardless I immedietely ap

I am a phd student, I sent another student a vulgar text message when I was drunk, woke up apologized but she slapped a sexual harrassment case on me. We had been flirting back and forth on and off for a year via text messages but she claims I have been harrassing her for the whole time even though its clearly not and it is the opinion of the case worker that the flirting was 2 way.. It is up to a disciplinary committee now and I face expulsion. All of the texts were sent outside of work/school hours. She never told me to stop texting her or complimenting her, as a matter of fact at one point I did apologize for my compliments and flirting and she said did I say I had a problem with it, if I do I will tell you. I feel like a made a drunken mistake and apologized for it but now she wants to get even with me.