The question you ask is important, as it is a step toward understanding how what you have experienced has shaped who you have become. Ultimately, you are the expert regarding who you are and why.
Generally speaking, there are many people who are sexually abused who are not gay, and many LGBTQ individuals who were not sexually abused. There has not been a study that proves that childhood abuse leads to a shift in sexual orientation. Some studies suggest that there is larger percentage of abuse survivors in the LGBT community. Despite this, we cannot make assumptions that experiencing abuse led to being gay or the opposite, that being gay led to being abused. Of course, if an LGBTQ child is rejected by family or isolated from peers due to being perceived as “different,” it could be that the child is at a greater risk of being targeted by abusers who seek vulnerable children.