Thank you for your question.
If I understand your question correctly, you are trying to define your gender identity and how it relates to those around you. You seem to be quite far along in the process of deciding for yourself what your gender identity is. I congratulate you for this. It is certainly not an easy journey for anybody and is often filled with many strong emotions and many questions. It also seems that you have been able to be open about your feelings with your family. This is important as well. It is a step towards being accepted by others as you really are.
And if your family is supportive, they can be great allies in helping you along on your journey. Here are a few, perhaps though-provoking, questions, that you may want to ask yourself: (1) how do you see yourself as a person? (2) what part does gender identity play in defining you as a person? What things about you (your personality, your interests) are the same, no matter how you present? (3) what do you think your friends’ reaction will be when they learn? (4) what is the worst possible reaction that you can imagine? How would you deal with it? (5) what about the most positive reaction that you can imagine? How would it make you feel? (5) Can you think of one friend with whom you think you may share some of your thoughts and feelings about your gender identity and transitioning?
You may start by speaking to one friend and seeing his or her reaction. Alternatively, you can check out some of the online trans communities — you may find support, ideas, and perhaps even friends on forums there (see https://alterheros.com/english/network/ for a list of mostly North American organisations). On-line forums may be a less threatening environment to share your feelings on transitioning and gender identity.
I hope this helps. Please do write in if you have any other questions.
Rimma, for Alterheros.