Have you processed about whatever happened in high school? Like talked to the therapist? Maybe if you're able to get through the trauma it will make you feel more comfortable with the idea of your orientation? I think you brought it up twice so it must be a big thing that happened to you. Trauma can mess with your association of being gay and cause you to feel that negatively towards your orientation. That's why I would work on it. Especially if your first experience was that horrible.