Hi Fennekin! Coming out to those close to you is a huge step; I wish I had your courage. I'm waiting until I'm independent from my parents before I come out to any family members, and I'm so anxious about telling them.
Like RaptorChops said, the nice thing about high school is once you're done with that, you're likely to only keep in contact with those few people, if any, who you've bonded with, and if they don't take the news of you being trans well, then they probably aren't as close to you as they think. And finishing high school marks a step in starting the rest of your life, so to speak, and it sounds like you've already taken steps to make sure you live the life you want to live.