Of course you're scared, of course you're nervous. This is a big deal. You're 21 years old and making decisions that will affect, if not change, the rest of your life. That is heroic and brave. Are you seeing a gender specialist yet? If not, get thee hence! This is why counseling is such a big part of transition, and in my view ought to be a prerequisite for everyone who is at that crazy cusp of fully becoming an adult.
You are okay. Breathe, In for a count of three, hold for a count of three, release for a count of three. Do this until the panic is gone.
Mothers sometimes bark. It just is the way it is, but you are in control of how you spend the rest of your life. You are in control of how you relate to your own body and spirit. There is beauty in living authentically, there is joy in seeing yourself become who you really are. It takes time, it takes patience, it takes courage. It is something that many of us simply have to do.
This is neither wrong nor voluntary. It will be okay
Breathe.....
Julie