I had a similar problem with dating as you, actually, but not an identical problem. I do an excellent outgoing act. If I meet a stranger for dinner, I don't have any trouble being talkative and charming. I'm told I make "an excellent companion." I'll tell stories, listen carefully to yours, and ask you questions. I won't feel the least bit uncomfortable doing it.
But that talkative, charming person is only a very small part of who I am. In reality, I'm intensely private to the point of introverted sometimes. I seem to need lots of time to be either alone or at least to be very quiet. I like going out and being charming, but not very often. I'm a homebody. So a date's first impression of me is apt to give him the wrong idea, which can set up problems later on.
Oh, how complicated we humans are, eh?