Hi Kristen,
I think the answer to your problem is right in front of you -- you need to communicate. You actually say so right in your post. Perhaps you should ask yourself, if I am thinking about this person so much, why am I not reaching out or sharing my thoughts with him? Whatever the obstacle might be, it's not impossible to overcome it. Maybe you could put up a little sign in your house that says "Don't forget to communicate."

I also wanted to point out that the beginning of the relationship is a great time to discuss people's history as a part of getting to know them. Where they are from, what their family is like, the dorky things they did in high school. There are a huge number of things to talk about, but for some reason you feel there's not much to talk about in this stage. Extroverts want to know about you and share the important (and trivial) parts of themselves. It would really help you to think of the start of a relationship as the start of an exciting journey and not a stage to get through so you can finally talk a bit more. Change your expectations / assumptions. It will help you a lot.
Good luck!!