If you decide to see a therapist, it will be your decision and nobody else's. If you decide to transition, every decision will be your's as you have to live with the consequences. The default is for you to make no decisions and then you will remain as you are.
I suggest you go back to your
initial greeting post located here and review the link I gave you to Wiki and The transition Channel as you may find some of your answers in those links. Many times the age to start a transition is 18 years of age because this is an adult decision so you need to be an adult. Unfortunately being transgender can cause us to grow up early but you will need to make this decision as an adult.