Hey Mellissa,
I was in your situation a while back. I started transitioning when I was 15, because like you, I had supportive parents. You are very fortunate that they seem to be accepting. This is going to be quite a journey, so I would say definitely take a breath. SRS will be down the road, as you will need to be on hormones and seeing a therapist for a while before SRS comes into the picture. The best thing you can do now is find a good therapist who has experience with working with transgendered people (this may be easier if you are near a larger city) and from there you can start the process of transition with androgen blockers, estrogen and perhaps laser hair removal/electrolysis. Once you feel comfortable you can start living full-time as a girl.
I know surgery sounds like the best part of transitioning, but honestly, I feel that going full-time as a girl and being seen as female by the outside world was a much more meaningful accomplishment than the surgery. The surgery will give you a vagina, but being a woman is much more than just having a vagina.
Best of luck to you!
Andromeda