Help?? Friend keeps accusing me of being a snitch?

My EX friend not really even a friend just a school buddy and me got drunk in school before winter break a few months ago. I downed a water bottle of bacardi more then her plus shes fatter so i got more of an affect..anyway i got alcohol posining and blacked out in school i didnt even know wtf was going on or who i was like it was that bad and they almost had to pump my stumoch i had to go to the hospital and everything. well the teachers were badgering me about who i did it with and i gave her name out which i dont even remember. anyway months later she keeps tlakin **** behind my back and stuff about me being a snitch and im sick and tired of it! i was arguing with her @ lunch today and she was like u knew what u were doin and i was like id NEVER DO THAT IF I WAS ****** IN MY RIGHT STATE OF MIND. anyway help me out to get this to stop or tell her off??