I did it. I finally did it! I'm officially out to my family and those friends I'm still in touch with.
I started a couple of weeks ago when I talked to my best RL friend, and I told him everything. He was a little bit uncomfortable with it, but very accepting. He even seemed like he got more comfortable with the idea as we talked it over. I think it was the technical discussion of hormones that helped make it seem less weird - he loves geeky stuff like that, same as me. It was such a relief for him to be OK with it.
I talked to his sister the the next day - also my friend - and she was totally great about it. I haven't been friends with her as long, so she has less invested in the "old me", I guess. She's been an LGBT-rights advocate since grade school, and is in a lesbian partnership herself, so I felt really safe coming out to her. We had an hour-long conversation over Skype (she lives in Ireland) where I told her everything.
My parents, I just told last night - on Easter. I didn't plan it that way for symbolism or anything, the logistics just worked out that way. It was... different than I expected. Very different.
My father actually seemed the most accepting of it, when I was afraid he might go so far as to throw me out and disown me. His attitude was "You do what you need to do to be happy in your own life." His biggest concern was that I'm self-medicating, and he wants me to see a doctor for that as soon as possible. That seemed to bother him way more than the fact that I'm transitioning.
My mother just kind of sat there with teary eyes the whole time, and didn't say much. She was more disturbed by it than my father, and she was also worried about consequences for me - could I ever find someone to be with, would I be attacked for being this way, etc. She''s nominally OK with it, in the "It's your life" sense, but she seemed disappointed. I hope she comes around, but it's still a better reception than I ever hoped for. She did actually make a joke about not knowing how to handle TWO daughters

I told my 14 year old sister just after - the one I've always had a bad relationship with - and she was like, "meh". It didn't faze her at all. I was honestly hoping an intense reaction, one way or the other, so I kept trying to provoke one by telling her more and more about it. No good, she was just OK with me being that way

I do hope that we have a sisterly relationship and put a lot of the old fights behind us, but we'll see.
So here I am. I have a home, a family, and a future. I can dress and be myself and transition without being afraid of the people I love anymore. I can be a daughter and a big sister, and I feel so liberated that I honestly don't know what to do now. The fear was my companion for two decades, and I don't quite know HOW to be free yet