Telling the parental units is the hardest thing to do. What will they say? What will they do? Will I be supported or disowned? What will I do if they want me to leave?
These things are scary, but we must face them. If you do not will be 54 years old and just starting your life as a woman. Trust me on this one, for that is exactly what I did do. I never told, lived the life of a man and have attempt to end it all three times at least. The least of your worries is what will they do. You need to focus on what will I do.
Live their way till one day I put a Glock in my mouth and pull the trigger. Or tell them that I have to do this. Would rather me be here as you I am. Or would you rather have me in a pine box.
And if they would rather you die, then walk out of their miserable little lives and be you anyway. The best thing you can do it to stand up for yourself and be you. Don't let them push you around.
Yes it is harder when you have to depend on them for insurance, housing, food. But in that case get out get some kind of job, if you can, and become emancipated.
There is several examples of how to tell the parents in the Reference Section above.