Like spacial said, it takes a long time to fully understand your own gender identity.
The best thing I can suggest is to read as much as you can and interact with other people in the same position as you. Also, seeing a therapist can be extremely helpful to talk about these feelings and anything else that may be bothering you.
Lastly, surgery should be the last thing you are thinking about right now. Many other things like coming out, hormones and transitioning come before that. Plenty of people don't even get surgery.