I completely understand where you are coming from, SC. I am the same way. I feel no attraction to strangers. The emotional level has to be up to par, but even if it is, there is no guarantee love or any attraction will ever follow. I have to be in love in order to feel sexual attraction. The last time I fell in love was almost 14 years ago.
When I met my husband, I did not know I would marry him or even end up in a relationship with him. There was no way for me to know. I appreciated him from an aesthetic point of view, but I never once thought, "He is sexy. I want him right now." The attraction came months later, and it was not something I recognised. It was just like, "This is something unfamiliar, but I like it." An actual relationship did not blossom until almost a year later.
I have never been able to definitively say, "XYZ is attractive," because that would be a one-size fits all thing. That is not the case. With Mr. Handprints, his confidence, intelligence, personality, etc. are attractive to me. At the same token, I could be in a room with Mr. GQ who possesses a magnetic personality, confidence out of this world, and an IQ to rival Einstein's, but my interest in him would be nonexistent.
Who knows what happened with the OP's ex? It could very well be like you described. The only one who has the answer to that is the ex. It could be that she was just bi-curious but realised an actual relationship is not what she desired. I am not sure if the OP asked how she came to the conclusion, but it might lessen the anger, if she could ask some questions.
OP, there are people who play with emotions like it is a 9-5, but your ex's intentions may not stem from a place of wanting to intentionally hurt you. She may not have had any interest in stringing you along. Circumstances change. I know you are hurting and angry, but if you are up to it, I would say talk to her.
Ry - Me. Panromantic demisexual with a history of polyamorist tendencies. Married to...
Matt (Hubby) - The once distant stranger that I complement beautifully. DH of 13 years and father of our four children.