I think it is probably very confusing for her at the moment and you are being caught in the crossfire. I understand that it is confusing for you as well because you are trying to figure out whether it was all a lie and you should know that it wasn't a lie. The feelings she had for you will have been real but as she has developed her feelings have changed. She probably still feels an attraction for you which makes it confusing for her and why she is still flirting. However, ultimately, if she is a lesbian then you are not what she wants, but that doesn't mean she never had feelings for you or doesn't care.