Sounds like they'll come around in good time, the initial shock may just have been a bit much for them.
Maybe later, you can calmly sit down with them and explain just how long you've known this and just how long you've been pursuing the change in self (as in, the time between now and the day you first wanted to bind and/or pack).
The calmer you are, the better.
Cause calm = serious in most people's minds. If you present your case in a calm, matter of fact, sort of way, they're more likely to accept it. (Which does mean you have to speak to them like an equal a bit too.)