Hi Beverly Rose
If it is a version of the Christian faith you are up against, the argument can be stated in an easy to understand manner. (and if your parents are reading this, I would be happy to discuss it with them - I have studied Theology, and know of a number of well respected theologians that support this position - Francis Schaeffer and James Dobson for starters.)
Christianity suggests:
The way you were born is not necessarily the way you were meant to be.
That is, from a reading of Genesis we find out that when sin entered the world it affected not just our souls, but all of creation, (physical, mental, and spiritual.)
As such, a child born with deformed hands and feet, (like I was,) is not necessarily the way they were meant to be. A child born with an autism spectrum disorder, (like I was,) is not necessarily the way they were meant to be. A child born with the physical appearance of both male and female genitalia is not necessarily the way God intended them to be. And a transgender child, born with the genitalia of the wrong sex is not necessarily the way God intended them to be.
In Christian ideology, sin is not a choice - it's a fact of life that affects our entire being.
However, Christian ideology also tells us that, despite our 'fallen' nature, God still loves us, and wants only what is good for us. Jesus never rejected individuals affected by sin. The Gospels are full of instances in which Jesus willingly accepts such individuals, and frees them of the guilt imposed by their communities. If your parents reject YOU, they are not following the teaching of Christ - to love others as they are loved by God.
The main message of Bible based Christianity is one of hope. "Faith is the essence of things hoped for." It is not absolute knowledge of right and wrong, or good and evil.
Your situation, while it may feel horrible, is not hopeless.