BBGURL I think should take your time, especially when you are having issues with doubt. Inform yourself on what it means to be trans, explore your feelings, and try to recognize what the source of your doubt is. I see this is in the youth section and I realize that you might be in a hurry to either stop or prevent puberty. It's hard I know, but I think you have to move at a pace that doesn't flip the world upside down in very little time. Moving too fast can be to much change all at once. Give your emotions time to catch up to your mind. It's a lot to comprehend.
I would recommend seeing a gender therapist. They can help you with your doubt and they can help you find doctors if a medical transition is right for you.
Also move at your own pace. Nothing about a transition is fast paced the hormones usually work pretty slow. There is no list of things that you have to do first in order to transition successfully, aside from surgery in some State/countries.