Congrats to your big first step. I would watch for any changes as you begin to live your life, and present as your opposite apparent birth gender. I've seen many cases where people initially said some words of support, only to later do a 180 as they blame the new you for taking away your old self from them. Also, be on guard as your family starts to talk to others outside the family. Sometimes they carry their own baggage and will work to dissuade your family from their position of support for you.
Good luck, and keep us all posted!