Everything Dena has said is good advice. A few other points:
- If you're just now starting therapy, it may take a while to get to the point where they're willing to give you a referral. I'm guessing that the school year is just starting where you are? I would be very surprised if someone was willing to make a referral prior to the school year being over - but it really depends. Either way, I would focus more on getting the most you can out of therapy while socially transitioning instead of just checking off the box and waiting for your referral.
- What are your plans for after graduation? You're poised to be in a good place when you go off to college if you start legally transitioning this year. Get your name changed, get it updated with the school you'll be going to. See if you can get it updated on your current school records. That'll make your life so much easier.
- Socially, high school becomes a complete joke after you're done. It seems really serious when you're there. Things can get dramatic when you're around the same group of people 8 hours a day, 5 days a week. If your friends know about your transition and are accepting of you, I wouldn't worry about anyone else. It's a mental shift you'll have to make, but in the grand scheme of life, the sooner you can get over caring about what random people think, the better off you will be.