HOTLINE
Suicide, without doubt WILL hurt them, And if your not out, you dont know how they will react, truth be told, yes you can have a good idea, but somtimes people can surprise you.
But thier is a chance not matter how slim, that comming out will not hurt them as much.
I loved my family, and putting their happyness before my own was a mistake that led me to such horrible thoughts.
EDIT:
You say, you dad keeps saying your his only daughter, His little girl.
I was my fathers only son. And hearing this was painfull it hurt. So I can feels some of the emotional torment this gives you.
When I say my dad called me his only son, this was because he disowned my gay brother, in so much my dad no longer saw him as a man, a son. so all of those dreams, hopes and desires for a son all fell on my shoulders.
And with him disowning my gay brother, I felt that I too would be disowned.
Even though I knew for a fact, it was possible for my dad to disown a child. He did not disown me.
After I came out, my dad hurt. Yes but, not nearly as much as I though.
My dad, got back in touch with my brother. And now me, my dad and my brother have a much better bond.
No matter how dark things might seem, it might not be as bad as you fear. And I can almost say for a sure that there will be sombody here in a similer situation, to help you through it, no matter how bad things get.