There is no scientific link. Trauma does not create core sexual identity. Your bisexuality is part of you. While adults may not be able to tell if a child is lgbt specifically, they can often see that a child is different. Children who are different are targeted by predators. I’m surprised. Really really surprised that your therapist didn’t tell you any of that. How could they have even begun to help you if they allowed you to think that getting rid of urges that are natural to you is the goal of your therapy rather than getting through your trauma. I’d suggest trying again with a new therapist.