I think it's important to discuss these things early on in a relationship. My girlfriend and I are both very independent people (she's an introvert, I'm an extrovert, but we're both independent), so we don't feel the "need" to talk to each other daily. We'd like to give each other some space.
We discussed "contact frequency" early in the relationship, and established on a mutual agreement that we'll not need to contact each other every single day. Of course we'd leave each other a good morning or sweet dreams sort of thing, along with links to interesting articles to read and discuss together. But we established that there will be no pressure to call/text each other daily. She is an introvert, so it would drain her energy; I'm an extrovert, so I need to be exploring the broader world on my own and diversify my human contact.
In our case, it makes the relationship strong and spicy - a little bit of space help us develop ourselves by pursuing our respective interests and meeting our own friends, thus making us more interesting persons for each other in the long run. So yeah, tell him in a matter-of-fact way that you need some space for personal reasons because you're an introvert. Even after you carefully tell him who you are, if he does not accept it and gets pissy about it instead, he doesn't deserve you.