Male? Female?

Probably not everybody will agree with me, but I guess when you first discover being trans* you're not like "hey, I'm actually male/female". It definitely is a progress.

My therapist asked me, what I would answer if someone asked me (in an uninsulting way) about my gender.
And I really didn't know what to say. I know I don't feel female. But I also don't feel fully male (yet?).
So I just said: "Probably 'both'.", and I think that is accurate regarding my current situation - genderfluid?

But after that she asked me, how I would introduce myself - and that was even more difficult to answer.
No one calls me "Jo" yet, because nobody knows I'm trans*, but I'd like to change that when moving away for university. Still, it will probably feel weird being called a "different" name - although it would really be a relief.
I ended up saying "My ... name (birthname) ... ?", so it was rather a question. I really don't know, what I'm going to do about that.
Why am I so shy and unsure?

And, by the way, nobody knows about my chosen name "Jonah" yet - just about the nickname - because I'm kinda afraid they won't like it.
And yes, I know that shouldn't matter, because it's my life and my name - but it still does.