The purpose of dating is so each person can get to know who the other person really is.
Many of us wear a mask, especially when first meeting someone we are interested in and want to impress. While you may have thought you got to know the real her long ago, it seems it took 2 years for her to reveal her other personality, the cult personality.
Right now, you don't seem to care much for her other personality, so are you prepared to live with that personality for the remainder of your life? If not, the time invested in the relationship was not wasted or a failure but is the price paid before proceeding on to the relationship's next stage, to help ensure you both haven't chosen the wrong person to commit to and share the remainder of your life with.