If you were abused by your stepfather, isn't it possible that your intrinsic tendency was that of a heterosexual but that the abuse made homosexuality feel safer? I am a firm believer that environment does play a role in sexual tendencies, and I have struggled with my own sexual identity for a time after being abused by various men. Now that you have undergone therapy, perhaps the "real you" and your true tendencies don't need to be hidden like before.