Perhaps you should stop trying to intervene on his behalf with other family members. I suspect he didn't ask for this. I think that all he wants from you is to support him, acknowledge his gender preference, and treat him respectfully. Stop asking questions of any nature revolving around his identity. Support him and love him. In time, once you've restored good communication, ask HIM how you can best support him.
I’ll take ‘Asking a Question You Don’t Really Want The Answer To’ for $400 Alex.
Perhaps you should stop trying to intervene on his behalf with other family members. I suspect he didn't ask for this. I think that all he wants from you is to support him, acknowledge his gender preference, and treat him respectfully. Stop asking questions of any nature revolving around his identity. Support him and love him. In time, once you've restored good communication, ask HIM how you can best support him.